Set latest tag based on branch in sdk and docker snapshots (#36298)

* Set latest tag based on branch in sdk and docker snapshots

* cleaner conditional logic

Author: ksobrenat32

.github/workflows/beam_Publish_Beam_SDK_Snapshots.yml

@@ -91,6 +91,9 @@ jobs:
         run: |
           BEAM_VERSION_LINE=$(cat gradle.properties | grep "sdk_version")
           echo "BEAM_VERSION=${BEAM_VERSION_LINE#*sdk_version=}" >> $GITHUB_ENV
+      - name: Set latest tag only on master branch
+        if: github.ref == 'refs/heads/master'
+        run: echo "LATEST_TAG=,latest" >> $GITHUB_ENV
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v1
       - name: Authenticate on GCP
@@ -120,6 +123,6 @@ jobs:
           arguments: |
             -Pjava11Home=$JAVA_HOME_11_X64 \
             -Pdocker-repository-root=gcr.io/apache-beam-testing/beam-sdk \
-            -Pdocker-tag-list=${{ github.sha }},${BEAM_VERSION},latest \
+            -Pdocker-tag-list=${{ github.sha }},${BEAM_VERSION}${LATEST_TAG} \
             -Pcontainer-architecture-list=arm64,amd64 \
             -Ppush-containers \

.github/workflows/beam_Publish_Docker_Snapshots.yml

@@ -70,6 +70,9 @@ jobs:
           github_job: ${{ matrix.job_name }} (${{ matrix.job_phrase }})
       - name: Setup environment
         uses: ./.github/actions/setup-environment-action
+      - name: Set latest tag only on master branch
+        if: github.ref == 'refs/heads/master'
+        run: echo "LATEST_TAG=,latest" >> $GITHUB_ENV
       - name: GCloud Docker credential helper
         run: |
           gcloud auth configure-docker ${{ env.docker_registry }}
@@ -79,11 +82,11 @@ jobs:
           gradle-command: :runners:spark:3:job-server:container:dockerPush
           arguments: |
             -Pdocker-repository-root=gcr.io/apache-beam-testing/beam_portability \
-            -Pdocker-tag-list=latest \
+            -Pdocker-tag-list=${{ github.sha }}${LATEST_TAG}
       - name: run Publish Docker Snapshots script for Flink
         uses: ./.github/actions/gradle-command-self-hosted-action
         with:
           gradle-command: :runners:flink:1.17:job-server-container:dockerPush
           arguments: |
             -Pdocker-repository-root=gcr.io/apache-beam-testing/beam_portability \
-            -Pdocker-tag-list=latest
+            -Pdocker-tag-list=${{ github.sha }}${LATEST_TAG}