Added CI for platform interface.

Author: mvanbeusekom

.github/workflows/google_api_availability_platform_interface.yaml

@@ -0,0 +1,55 @@
+# This is a basic workflow to help you get started with Actions
+name: google_api_availability_platform_interface
+
+# Controls when the action will run. Triggers the workflow on push or pull request
+# events but only for the main branch
+on:
+  push:
+    branches: [ main ]
+    paths:
+    - 'google_api_availability_platform_interface/**'
+  pull_request:
+    branches: [ main ]
+    paths:
+    - 'google_api_availability_platform_interface/**'
+
+# A workflow run is made up of one or more jobs that can run sequentially or in parallel
+jobs:
+  build:
+    name: Format
+
+    # The type of runner that the job will run on
+    runs-on: ubuntu-latest
+
+    env:
+      source-directory: ./google_api_availability_platform_interface 
+
+    # Steps represent a sequence of tasks that will be executed as part of the job
+    steps:
+      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
+      - uses: actions/checkout@v3
+      
+      # Make sure the stable version of Flutter is available
+      - uses: subosito/flutter-action@v2
+        with:
+          channel: 'stable'
+
+      # Download all Flutter packages
+      - name: Download dependencies
+        run: flutter pub get
+        working-directory: ${{env.source-directory}}
+
+      # Run Flutter Format to ensure formatting is valid
+      - name: Run Flutter Format
+        run: flutter format --set-exit-if-changed .
+        working-directory: ${{env.source-directory}}
+   
+      # Run Flutter Analyzer
+      - name: Run Flutter Analyzer
+        run: flutter analyze
+        working-directory: ${{env.source-directory}}
+      
+      # Run all unit-tests with code coverage
+      - name: Run unit tests
+        run: flutter test --coverage
+        working-directory: ${{env.source-directory}}