[build] setup public pipeline on dnceng-public (#10636)

This updates the Azure Pipelines YAML configuration for .NET for
Android to include public CI on dnceng (.NET Core Engineering) AzDO
instance.

Key changes include:

**Pipeline Modularity and Refactoring**
- Added `build-macos-steps.yaml` and `build-linux-steps.yaml`
  templates to encapsulate platform-specific build logic, making it
  reusable and independent of private repos.
- Updated `azure-pipelines-public.yaml` to use these new templates,
  simplifying stage and job definitions for public builds.

**Linux Build Pipeline Improvements**
- Refactored `build-linux.yaml` to remove inline build steps and
  instead invoke the new `build-linux-steps.yaml` template, reducing
  duplication and centralizing logic.

**Artifact Handling Standardization**
- Unified the process for copying, deleting, packaging, and publishing
  build artifacts (including NuGet packages, symbols, test assemblies,
  and toolchain pdbs) within the new templates for both macOS and
  Linux.

**Pipeline Parameters and Test Skipping Logic**
- Enhanced parameterization and variable logic in
  `azure-pipelines-public.yaml` to control test execution and agent
  selection, including auto-skipping tests for non-fork PRs.

Author: jonathanpeppers

build-tools/automation/azure-pipelines-public.yaml

@@ -0,0 +1,359 @@
+# .NET for Android Pipeline - Public Build
+# This pipeline runs on the public dnceng instance for:
+# - PRs from forks (contributors)
+# - Main or release branch CI builds
+# Internal branches use the DevDiv pipeline (azure-pipelines.yaml)
+
+name: $(Build.SourceBranchName)-$(Build.SourceVersion)-$(Rev:r)
+
+trigger:
+  branches:
+    include:
+    - main
+    - release/*
+
+pr:
+  branches:
+    include:
+    - main
+    - release/*
+
+parameters:
+- name: macTestAgentsUseCleanImages   # Test agents we do not need to clean up when finished because they are not reused
+  default: true
+- name: skipTests                      # Skip all test stages (builds only). Use 'auto' to auto-skip for non-fork PRs.
+  displayName: Skip Tests
+  type: string
+  default: 'auto'
+  values:
+  - 'auto'
+  - 'true'
+  - 'false'
+
+# Repository resources - checkout android-tools to force multi-repo checkout behavior
+resources:
+  repositories:
+  - repository: android-tools
+    type: github
+    name: dotnet/android-tools
+    endpoint: public
+    ref: refs/heads/main
+
+# Global variables
+variables:
+- template: /build-tools/automation/yaml-templates/variables.yaml@self
+# Override for public pipeline
+- name: DefaultJavaSdkMajorVersion
+  value: 21
+# Override pool images for public Microsoft-hosted agents
+- name: HostedMacImage
+  value: macOS-14
+- name: LinuxPoolImage
+  value: ubuntu-22.04
+- name: NetCorePublicPoolName
+  value: NetCore-Public
+- name: WindowsPoolImageNetCorePublic
+  value: windows.vs2022.amd64.open
+- name: LinuxPoolImageNetCorePublic
+  value: build.Ubuntu.2204.amd64.open
+# Skip tests for non-fork PRs (they should use DevDiv pipeline) unless explicitly requested
+- name: SkipTestStages
+  ${{ if eq(parameters.skipTests, 'true') }}:
+    value: true
+  ${{ elseif eq(parameters.skipTests, 'false') }}:
+    value: false
+  ${{ elseif and(eq(variables['Build.Reason'], 'PullRequest'), ne(variables['System.PullRequest.IsFork'], 'True')) }}:
+    value: true
+  ${{ else }}:
+    value: false
+
+# Public builds don't use 1ES templates - just plain stages
+stages:
+# macOS Build Stage
+- stage: mac_build
+  displayName: Mac
+  jobs:
+  - job: mac_build_create_installers
+    displayName: macOS > Build
+    pool:
+      name: Azure Pipelines
+      vmImage: $(HostedMacImage)
+      os: macOS
+    timeoutInMinutes: 240
+    cancelTimeoutInMinutes: 5
+    workspace:
+      clean: all
+    steps:
+    - checkout: self
+      path: s/android
+      persistCredentials: false
+
+    # Checkout a second repo to force multi-repo checkout behavior
+    # https://learn.microsoft.com/en-us/azure/devops/pipelines/repos/multi-repo-checkout?view=azure-devops#checkout-path
+    - checkout: android-tools
+      path: s/android-tools
+
+    - template: /build-tools/automation/yaml-templates/build-macos-steps.yaml
+      parameters:
+        xaSourcePath: $(System.DefaultWorkingDirectory)/android
+        installerArtifactName: $(InstallerArtifactName)
+        nugetArtifactName: $(NuGetArtifactName)
+        testAssembliesArtifactName: $(TestAssembliesArtifactName)
+        windowsToolchainPdbArtifactName: $(WindowsToolchainPdbArtifactName)
+        buildResultArtifactName: Build Results - macOS
+        use1ESTemplate: false
+
+# Windows Build Stage
+- stage: win_build_test
+  displayName: Windows
+  dependsOn: []
+  jobs:
+  - job: win_build_test
+    displayName: Windows > Build & Smoke Test
+    pool:
+      name: $(NetCorePublicPoolName)
+      demands:
+      - ImageOverride -equals $(WindowsPoolImageNetCorePublic)
+    timeoutInMinutes: 240
+    steps:
+    - checkout: self
+      persistCredentials: false
+
+    - template: /build-tools/automation/yaml-templates/build-windows-steps.yaml
+      parameters:
+        buildResultArtifactName: Build Results - Windows
+        use1ESTemplate: false
+
+# Linux Build Stage
+- stage: linux_build
+  displayName: Linux
+  dependsOn: []
+  jobs:
+  - job: linux_build_create_sdk_pack
+    displayName: Linux > Build
+    pool:
+      name: $(NetCorePublicPoolName)
+      demands:
+      - ImageOverride -equals $(LinuxPoolImageNetCorePublic)
+    timeoutInMinutes: 240
+    workspace:
+      clean: all
+    variables:
+      CXX: g++-10
+      CC: gcc-10
+    steps:
+    - checkout: self
+      path: s/android
+      persistCredentials: false
+
+    # Checkout a second repo to force multi-repo checkout behavior
+    - checkout: android-tools
+      path: s/android-tools
+
+    - script: |
+        sudo apt-get update
+        sudo apt-get install -y g++-10 gcc-10
+      displayName: install g++-10 and gcc-10
+
+    - template: /build-tools/automation/yaml-templates/build-linux-steps.yaml
+      parameters:
+        buildResultArtifactName: Build Results - Linux
+        xaSourcePath: $(System.DefaultWorkingDirectory)/android
+        nugetArtifactName: $(LinuxNuGetArtifactName)
+        use1ESTemplate: false
+
+# Package Tests Stage
+- ${{ if ne(variables.SkipTestStages, 'true') }}:
+  - template: /build-tools/automation/yaml-templates/stage-package-tests.yaml
+    parameters:
+      macTestAgentsUseCleanImages: ${{ parameters.macTestAgentsUseCleanImages }}
+      use1ESTemplate: false
+
+# Linux Tests Stage
+- stage: linux_tests
+  displayName: Linux Tests
+  dependsOn: 
+  - mac_build
+  - linux_build
+  condition: and(succeeded(), ne(variables['SkipTestStages'], 'true'))
+  jobs:
+  - job: linux_tests_smoke_1
+    displayName: Linux > Tests > MSBuild 1
+    pool:
+      name: $(NetCorePublicPoolName)
+      demands:
+      - ImageOverride -equals $(LinuxPoolImageNetCorePublic)
+    timeoutInMinutes: 180
+    workspace:
+      clean: all
+    steps:
+    - template: /build-tools/automation/yaml-templates/setup-test-environment-public.yaml
+      parameters:
+        useAgentJdkPath: false
+        use1ESTemplate: false
+
+    - task: DownloadPipelineArtifact@2
+      inputs:
+        artifactName: $(TestAssembliesArtifactName)
+        downloadPath: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)
+
+    - template: /build-tools/automation/yaml-templates/run-nunit-tests.yaml
+      parameters:
+        testRunTitle: Xamarin.Android.Build.Tests - Linux BuildTest
+        testAssembly: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)/$(DotNetStableTargetFramework)/Xamarin.Android.Build.Tests.dll
+        dotNetTestExtraArgs: --filter "Name = BuildTest"
+
+    - template: /build-tools/automation/yaml-templates/upload-results.yaml
+      parameters:
+        configuration: $(XA.Build.Configuration)
+        artifactName: Test Results - MSBuild - Linux 1
+        use1ESTemplate: false
+
+    - template: /build-tools/automation/yaml-templates/fail-on-issue.yaml
+
+  - job: linux_tests_smoke_2
+    displayName: Linux > Tests > MSBuild 2
+    pool:
+      name: $(NetCorePublicPoolName)
+      demands:
+      - ImageOverride -equals $(LinuxPoolImageNetCorePublic)
+    timeoutInMinutes: 180
+    workspace:
+      clean: all
+    steps:
+    - template: /build-tools/automation/yaml-templates/setup-test-environment-public.yaml
+      parameters:
+        useAgentJdkPath: false
+        use1ESTemplate: false
+
+    - task: DownloadPipelineArtifact@2
+      inputs:
+        artifactName: $(TestAssembliesArtifactName)
+        downloadPath: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)
+
+    - template: /build-tools/automation/yaml-templates/run-nunit-tests.yaml
+      parameters:
+        testRunTitle: Xamarin.Android.Build.Tests - Linux PackagingTest
+        testAssembly: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)/$(DotNetStableTargetFramework)/Xamarin.Android.Build.Tests.dll
+        dotNetTestExtraArgs: --filter "Name = PackagingTest"
+
+    - template: /build-tools/automation/yaml-templates/run-nunit-tests.yaml
+      parameters:
+        testRunTitle: Xamarin.Android.Build.Tests - Linux XASdkTests
+        testAssembly: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)/$(DotNetStableTargetFramework)/Xamarin.Android.Build.Tests.dll
+        dotNetTestExtraArgs: --filter "Name = XASdkTests & Name != XamarinLegacySdk"
+
+    - template: /build-tools/automation/yaml-templates/run-nunit-tests.yaml
+      parameters:
+        testRunTitle: Xamarin.Android.Build.Tests - Linux AndroidDependenciesTests
+        testAssembly: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)/$(DotNetStableTargetFramework)/Xamarin.Android.Build.Tests.dll
+        dotNetTestExtraArgs: --filter "Name = AndroidDependenciesTests"
+
+    - task: ShellScript@2
+      displayName: Test dotnet-local.sh
+      inputs:
+        scriptPath: dotnet-local.sh
+        args: >-
+          build samples/HelloWorld/HelloWorld/HelloWorld.DotNet.csproj
+          -p:AndroidSdkDirectory="$(HOME)/android-toolchain/sdk"
+          -bl:$(System.DefaultWorkingDirectory)/bin/Build$(XA.Build.Configuration)/build-helloworld.binlog
+
+    - template: /build-tools/automation/yaml-templates/upload-results.yaml
+      parameters:
+        configuration: $(XA.Build.Configuration)
+        artifactName: Test Results - MSBuild - Linux 2
+        includeBuildResults: true
+        use1ESTemplate: false
+
+    - template: /build-tools/automation/yaml-templates/fail-on-issue.yaml
+
+# MSBuild Tests Stage
+- stage: msbuild_dotnet
+  displayName: MSBuild Tests
+  dependsOn: mac_build
+  condition: and(succeeded(), ne(variables['SkipTestStages'], 'true'))
+  jobs:
+  - job: mac_msbuild_tests
+    strategy:
+      parallel: 10
+    displayName: macOS > Tests > MSBuild
+    pool:
+      name: Azure Pipelines
+      vmImage: $(HostedMacImage)
+      os: macOS
+    timeoutInMinutes: 240
+    cancelTimeoutInMinutes: 5
+    steps:
+    - template: /build-tools/automation/yaml-templates/setup-test-environment-public.yaml
+      parameters:
+        installTestSlicer: true
+        use1ESTemplate: false
+
+    - task: DownloadPipelineArtifact@2
+      inputs:
+        artifactName: $(TestAssembliesArtifactName)
+        downloadPath: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)
+
+    - template: /build-tools/automation/yaml-templates/run-sliced-nunit-tests.yaml
+      parameters:
+        testAssembly: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)/$(DotNetStableTargetFramework)/Xamarin.Android.Build.Tests.dll
+        testFilter: ''
+        testRunTitle: Xamarin.Android.Build.Tests - macOS
+        retryFailedTests: false
+        xaSourcePath: $(System.DefaultWorkingDirectory)
+
+    - template: /build-tools/automation/yaml-templates/upload-results.yaml
+      parameters:
+        artifactName: Test Results - MSBuild - macOS-$(System.JobPositionInPhase)
+        xaSourcePath: $(System.DefaultWorkingDirectory)
+        use1ESTemplate: false
+
+    - template: /build-tools/automation/yaml-templates/fail-on-issue.yaml
+      parameters:
+        condition: true
+
+  - job: win_msbuild_tests
+    strategy:
+      parallel: 8
+    displayName: Windows > Tests > MSBuild
+    pool:
+      name: $(NetCorePublicPoolName)
+      demands:
+      - ImageOverride -equals $(WindowsPoolImageNetCorePublic)
+    timeoutInMinutes: 240
+    cancelTimeoutInMinutes: 5
+    steps:
+    - script: netsh int ipv4 set global sourceroutingbehavior=drop
+
+    - template: /build-tools/automation/yaml-templates/kill-processes.yaml
+
+    - template: /build-tools/automation/yaml-templates/clean.yaml
+
+    - template: /build-tools/automation/yaml-templates/setup-test-environment-public.yaml
+      parameters:
+        useAgentJdkPath: false
+        installTestSlicer: true
+        use1ESTemplate: false
+
+    - task: DownloadPipelineArtifact@2
+      inputs:
+        artifactName: $(TestAssembliesArtifactName)
+        downloadPath: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)
+
+    - template: /build-tools/automation/yaml-templates/run-sliced-nunit-tests.yaml
+      parameters:
+        testAssembly: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)/$(DotNetStableTargetFramework)/Xamarin.Android.Build.Tests.dll
+        testFilter: ''
+        testRunTitle: Xamarin.Android.Build.Tests - Windows
+        retryFailedTests: false
+        xaSourcePath: $(System.DefaultWorkingDirectory)
+
+    - template: /build-tools/automation/yaml-templates/upload-results.yaml
+      parameters:
+        artifactName: Test Results - MSBuild - Windows-$(System.JobPositionInPhase)
+        xaSourcePath: $(System.DefaultWorkingDirectory)
+        use1ESTemplate: false
+
+    - template: /build-tools/automation/yaml-templates/fail-on-issue.yaml
+      parameters:
+        condition: true