java8/11 test for sdk-platform-java

Author: chingor13

.github/workflows/ci.yaml

@@ -45,6 +45,40 @@ jobs:
       env:
         JOB_TYPE: test
         JOB_NAME: units-${{matrix.java}}
+  units-8-runtime:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Get current week within the year
+      id: date
+      run: echo "::set-output name=week_of_year::$(date +'%W' --utc)"
+    - uses: actions/checkout@v4
+    - uses: actions/setup-java@v4
+      with:
+        java-version: 11
+        distribution: temurin
+        cache: maven
+    - run: java -version
+    - uses: actions/cache@v4
+      id: mvn-cache
+      with:
+        path: ~/.m2/repository
+        key: ${{ runner.os }}-maven-unified-${{ steps.date.outputs.week_of_year }}
+    - name: Install all modules using Java 11
+      shell: bash
+      run: |
+        mvn -V -B -ntp clean install -DskipTests -Dfmt.skip -Dclirr.skip -Denforcer.skip -Dcheckstyle.skip -Dflatten.skip -Danimal-sniffer.skip -Djacoco.skip
+      working-directory: sdk-platform-java
+    - uses: actions/setup-java@v4
+      with:
+        java-version: 8
+        distribution: temurin
+    - run: java -version
+    - name: Run tests in Java 8 with the source compiled in Java 11
+      run: .kokoro/build.sh
+      env:
+        JOB_TYPE: test
+        JOB_NAME: units-8-runtime-${{matrix.java}}
+      working-directory: sdk-platform-java
   windows:
     runs-on: windows-latest
     steps: