[xabt] remove Xamarin.Android.Bindings.targets and $(_AndroidIsBindingProject) (#10337)

Fixes: #10336

This PR removes the classic `Xamarin.Android.Bindings.targets` file and
all usage of the private `$(_AndroidIsBindingProject)` MSBuild
property, as these are only relevant for classic Xamarin.Android
binding projects and are not used in .NET 6+ projects.

## Changes Made

### Removed Legacy Files

- **Deleted `Xamarin.Android.Bindings.targets`** (172 lines) - This
  file was the entry point for legacy binding projects and is not
  imported by .NET 6+ projects

- **Removed reference** to the targets file from
  `Xamarin.Android.Build.Tasks.targets`

### Inlined `$(_AndroidIsBindingProject)` Logic

Since `$(_AndroidIsBindingProject)` can never be true in .NET 6+, the
logic has been simplified by:

- **Removing conditions that check `== 'True'`** - These blocks would
  never run
- **Removing conditions that check `!= 'True'`** - These blocks would
  always run, so the condition was removed
- **Keeping the logic that runs when the property is false/empty**

Co-authored-by: Jonathan Peppers <[email protected]>

Author: Copilot

src/Xamarin.Android.Build.Tasks/MSBuild/Xamarin/Android/Xamarin.Android.AvailableItems.targets

@@ -10,7 +10,7 @@ This item group populates the Build Action drop-down in IDEs.
 <Project>
 
   <!-- Not legacy binding projects -->
-  <ItemGroup Condition=" '$(_AndroidIsBindingProject)' != 'true' ">
+  <ItemGroup>
     <AvailableItemName Include="AndroidAotProfile" />
     <AvailableItemName Include="AndroidAsset" />
     <AvailableItemName Include="AndroidEnvironment" />

src/Xamarin.Android.Build.Tasks/Xamarin.Android.Bindings.targets

@@ -91,9 +91,6 @@
     <None Include="Xamarin.Android.Application.targets">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
-    <None Include="Xamarin.Android.Bindings.targets">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </None>
     <None Include="Xamarin.Android.Common.props">
       <SubType>Designer</SubType>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>

src/Xamarin.Android.Build.Tasks/Xamarin.Android.Build.Tasks.targets

@@ -50,7 +50,7 @@ This file is used by all project types, including binding projects.
       <_AndroidResgenFlagFile Condition=" '$(DesignTimeBuild)' == 'true' And !Exists('$(_AndroidResgenFlagFile)') ">$(_AndroidIntermediateDesignTimeBuildDirectory)R.cs.flag</_AndroidResgenFlagFile>
     </PropertyGroup>
     <MakeDir
-        Condition=" '$(_AndroidIsBindingProject)' != 'true' And !Exists ('$(_AndroidIntermediateDesignTimeBuildDirectory)') "
+        Condition=" !Exists ('$(_AndroidIntermediateDesignTimeBuildDirectory)') "
         Directories="$(_AndroidIntermediateDesignTimeBuildDirectory)"
     />
     <MakeDir

src/Xamarin.Android.Build.Tasks/Xamarin.Android.DesignTime.targets

@@ -87,11 +87,7 @@ This file is used by all project types, including binding projects.
   </Target>
 
   <PropertyGroup>
-    <_GetLibraryImportsDependsOnTargets Condition=" '$(_AndroidIsBindingProject)' == 'true' ">
-      _ExtractLibraryProjectImports;
-      _BuildLibraryImportsCache;
-    </_GetLibraryImportsDependsOnTargets>
-    <_GetLibraryImportsDependsOnTargets Condition=" '$(_AndroidIsBindingProject)' != 'true' ">
+    <_GetLibraryImportsDependsOnTargets>
       _ExtractLibraryProjectImports;
       _AddMultiDexDependencyJars;
       _BuildLibraryImportsCache;

src/Xamarin.Android.Build.Tasks/Xamarin.Android.EmbeddedResource.targets

@@ -17,11 +17,7 @@ projects.
   <UsingTask TaskName="Xamarin.Android.Tasks.ResolveJdkJvmPath" AssemblyFile="Xamarin.Android.Build.Tasks.dll" />
 
   <PropertyGroup>
-    <_SetLatestTargetFrameworkVersionDependsOnTargets Condition=" '$(_AndroidIsBindingProject)' == 'True'">
-      _ResolveSdks;
-      _ResolveAndroidTooling;
-    </_SetLatestTargetFrameworkVersionDependsOnTargets>
-    <_SetLatestTargetFrameworkVersionDependsOnTargets Condition=" '$(_AndroidIsBindingProject)' != 'True'">
+    <_SetLatestTargetFrameworkVersionDependsOnTargets>
       _ResolveSdks;
       _ResolveAndroidTooling;
       _InjectAaptDependencies;
@@ -83,7 +79,7 @@ projects.
         JavaSdkPath="$(_JavaSdkDirectory)"
         MinimumSupportedJavaVersion="$(MinimumSupportedJavaVersion)"
         LatestSupportedJavaVersion="$(LatestSupportedJavaVersion)"
-        Condition=" '$(DesignTimeBuild)' != 'True' And '$(_AndroidIsBindingProject)' != 'True' And '$(AndroidGenerateJniMarshalMethods)' == 'True' And '$(JdkJvmPath)' == '' ">
+        Condition=" '$(DesignTimeBuild)' != 'True' And '$(AndroidGenerateJniMarshalMethods)' == 'True' And '$(JdkJvmPath)' == '' ">
       <Output TaskParameter="JdkJvmPath"                PropertyName="JdkJvmPath" />
     </ResolveJdkJvmPath>
   </Target>