Refactor Android build workflow to streamline Docker image handling

Update GitHub Actions workflow to standardize image tagging and checking logic. Simplify condition handling for reusing existing Docker images or building new ones, ensuring consistent behavior and improved maintainability.

Author: anhappdev

.github/workflows/android-build-test.yml

@@ -18,15 +18,17 @@ jobs:
       packages: write
     steps:
       - uses: actions/checkout@v4
+
       - name: Get Dockerfile hash tag
         id: meta-hash
         uses: docker/metadata-action@v5
         with:
           images: ghcr.io/mlcommons/mobile_app_open-android
-          tags: type=content,path=flutter/android/docker/Dockerfile
+          tags: type=sha256,path=flutter/android/docker/Dockerfile
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
+
       - name: Log in to the Container registry
         uses: docker/login-action@v3
         with:
@@ -37,36 +39,33 @@ jobs:
       - name: Check if image exists
         id: check-image
         run: |
-          docker manifest inspect ${{ steps.meta-hash.outputs.tags }} > /dev/null
+          if docker manifest inspect ${{ steps.meta-hash.outputs.tags }} > /dev/null; then
+            echo "Image with Dockerfile hash tag exists."
+            echo "exists=true" >> $GITHUB_OUTPUT
+          else
+            echo "Image with Dockerfile hash tag does not exist."
+            echo "exists=false" >> $GITHUB_OUTPUT
+          fi
         continue-on-error: true
 
       - name: Pull and retag existing image
-        if: steps.check-image.outcome == 'success'
+        if: steps.check-image.outputs.exists == 'true'
         run: |
           docker pull ${{ steps.meta-hash.outputs.tags }}
           docker tag ${{ steps.meta-hash.outputs.tags }} ghcr.io/mlcommons/mobile_app_open-android:${{ github.run_number }}
           docker push ghcr.io/mlcommons/mobile_app_open-android:${{ github.run_number }}
 
-      - name: Extract metadata for new Docker image
-        if: steps.check-image.outcome != 'success'
-        id: meta-new
-        uses: docker/metadata-action@v5
-        with:
-          images: ghcr.io/mlcommons/mobile_app_open-android
-          flavor: latest=true
-          tags: |
-            type=raw,value=${{ github.run_number }}
-            type=content,path=flutter/android/docker/Dockerfile
-
       - name: Build and push new Docker image
-        if: steps.check-image.outcome != 'success'
+        if: steps.check-image.outputs.exists != 'true'
         uses: docker/build-push-action@v5
         with:
           context: flutter/android/docker
           file: flutter/android/docker/Dockerfile
           push: true
-          tags: ${{ steps.meta-new.outputs.tags }}
-          labels: ${{ steps.meta-new.outputs.labels }}
+          tags: |
+            ${{ steps.meta-hash.outputs.tags }}
+            ghcr.io/mlcommons/mobile_app_open-android:${{ github.run_number }}
+          labels: ${{ steps.meta-hash.outputs.labels }}
           cache-from: type=gha
           cache-to: type=gha,mode=max