chore: support WIF in example workflows

example-workflows/cloud-build/.github/workflows/cloud-build.yml

@@ -28,17 +28,32 @@ jobs:
     name: Setup, Build, and Deploy
     runs-on: ubuntu-latest
 
+    # Add "id-token" with the intended permissions.
+    permissions:
+      contents: 'read'
+      id-token: 'write'
+
     steps:
     - name: Checkout
       uses: actions/checkout@v2
 
-    # Setup gcloud CLI
-    - uses: google-github-actions/setup-gcloud@master
+    # Configure Workload Identity Federation and generate an access token.
+    - id: 'auth'
+      name: 'Authenticate to Google Cloud'
+      uses: 'google-github-actions/auth@v0'
       with:
-        version: '286.0.0'
-        service_account_email: ${{ secrets.RUN_SA_EMAIL }}
-        service_account_key: ${{ secrets.RUN_SA_KEY }}
-        project_id: ${{ secrets.RUN_PROJECT }}
+        workload_identity_provider: 'projects/123456789/locations/global/workloadIdentityPools/my-pool/providers/my-provider'
+        service_account: 'my-service-account@my-project.iam.gserviceaccount.com'
+
+    # Alternative option - authentication via credentials json
+    # - id: 'auth'
+    #   uses: 'google-github-actions/auth@v0'
+    #   with:
+    #     credentials_json: '${{ secrets.GCP_CREDENTIALS }}'
+
+    # Setup gcloud CLI
+    - name: Set up Cloud SDK
+      uses: google-github-actions/setup-gcloud@v0
 
     # Build and push image to Google Container Registry
     - name: Build