Fix PostCommit Java Examples Dataflow V2 workflow (apache#35015)

* Fix PostCommit Java Examples Dataflow V2 workflow

* Remove unnecessary DOCKER_TAG declaration

Author: akashorabek

.github/workflows/beam_PostCommit_Java_Examples_Dataflow_V2.yml

@@ -83,15 +83,25 @@ jobs:
         uses: ./.github/actions/setup-environment-action
         with:
           java-version: 17
+      - name: Set DOCKER_TAG unique variable based on timestamp
+        run: echo "DOCKER_TAG=$(date +'%Y%m%d-%H%M%S%N')" >> $GITHUB_ENV
+      - name: GCloud Docker credential helper
+        run: |
+          gcloud auth configure-docker us.gcr.io
       - name: run PostCommit Java Distroless Examples Dataflow V2 script
         uses: ./.github/actions/gradle-command-self-hosted-action
+        env:
+          USER: github-actions
         with:
             gradle-command: :runners:google-cloud-dataflow-java:examplesJavaRunnerV2IntegrationTestDistroless
             max-workers: 12
-            arguments:
-              -PskipCheckerFramework
-              -PtestJavaVersion=17
-              -Pjava17Home=$JAVA_HOME_17_X64
+            arguments: |
+              -PdisableSpotlessCheck=true \
+              -PdisableCheckStyle=true \
+              -PskipCheckerFramework \
+              -PtestJavaVersion=java17 \
+              -Pjava17Home=$JAVA_HOME_17_X64 \
+              -PdockerTag=${{ env.DOCKER_TAG }} \
       - name: Archive JUnit Test Results
         uses: actions/upload-artifact@v4
         if: ${{ !success() }}

runners/google-cloud-dataflow-java/build.gradle

@@ -329,7 +329,7 @@ tasks.register('buildAndPushDistrolessContainerImage', Task.class) {
               '-t',
               imageURL,
               '-f',
-              'sdks/java/container/Dockerfile-distroless',
+              'sdks/java/container/distroless/Dockerfile',
               "--build-arg=BEAM_BASE=gcr.io/apache-beam-testing/beam-sdk/beam_${javaVer}_sdk",
               "--build-arg=DISTROLESS_BASE=gcr.io/distroless/${javaVer}-debian12",
               '.'