Fix the generated unique tag for Java and Python multi-arch containers (#28003)

* Find another way to generate unique tag

* Unique tag for Java

* Fix syntax.

* changed to use output parameter instead.

.github/workflows/beam_PostCommit_Java_Examples_Dataflow_ARM.yml

@@ -56,9 +56,6 @@ permissions:
   security-events: read
   statuses: read
 
-env:
-  TAG: $(date +'%Y%m%d-%H%M%S%N')
-
 jobs:
   beam_PostCommit_Java_Examples__Dataflow_ARM:
     name: ${{matrix.job_name}} (${{matrix.job_phrase}} ${{matrix.java_version}}) 
@@ -111,6 +108,9 @@ jobs:
       - name: GCloud Docker credential helper
         run: |
           gcloud auth configure-docker us.gcr.io
+      - name: Generate TAG unique variable based on timestamp
+        id: set_tag
+        run: echo "TAG=$(date +'%Y%m%d-%H%M%S%N')" >> $GITHUB_OUTPUT
       - name: run javaExamplesDataflowARMPostCommit script for Java${{ matrix.java_version }}
         uses: ./.github/actions/gradle-command-self-hosted-action
         with:
@@ -121,7 +121,7 @@ jobs:
                 -Pcontainer-architecture-list=arm64,amd64 \
                 -Ppush-containers \
                 -Pdocker-repository-root=us.gcr.io/apache-beam-testing/github-actions \
-                -Pdocker-tag=${{env.TAG}} \
+                -Pdocker-tag=${{ steps.set_tag.outputs.TAG }} \
                 -PdisableSpotlessCheck=true \
                 -PdisableCheckStyle=true \
                 -PskipCheckerFramework \

.github/workflows/beam_Python_ValidatesContainer_Dataflow_ARM.yml

@@ -63,8 +63,6 @@ jobs:
       startsWith(github.event.comment.body, 'Run Python ValidatesContainer Dataflow ARM')
 
     runs-on: [self-hosted, ubuntu-20.04, main]
-    env:
-      MULTIARCH_TAG: $(date +'%Y%m%d-%H%M%S%N')
     steps:
       - uses: actions/checkout@v3
       - name: Setup repository
@@ -99,6 +97,9 @@ jobs:
           PY_VER=${{ matrix.python_version }}
           PY_VER_CLEAN=${PY_VER//.}
           echo "py_ver_clean=$PY_VER_CLEAN" >> $GITHUB_OUTPUT
+      - name: Generate TAG unique variable based on timestamp
+        id: set_tag
+        run: echo "TAG=$(date +'%Y%m%d-%H%M%S%N')" >> $GITHUB_OUTPUT
       - name: run Python validatesContainerARM script
         id: run_script
         uses: ./.github/actions/gradle-command-self-hosted-action
@@ -108,10 +109,10 @@ jobs:
             -PpythonVersion=${{ matrix.python_version }} \
             -Pcontainer-architecture-list=arm64,amd64 \
             -Pdocker-repository-root=us.gcr.io/apache-beam-testing/github-actions \
-            -Pdocker-tag=${{ env.MULTIARCH_TAG }} \
+            -Pdocker-tag=${{ steps.set_tag.outputs.TAG }} \
             -Ppush-containers \
         env:
-          MULTIARCH_TAG: ${{ env.MULTIARCH_TAG }}
+          MULTIARCH_TAG: ${{ steps.set_tag.outputs.TAG }}
           USER: github-actions
       - name: Archive code coverage results
         uses: actions/upload-artifact@v3