Update showcase.yaml

Author: nnicolee

.github/workflows/showcase.yaml

@@ -115,13 +115,46 @@ jobs:
         env:
           BUILD_SUBDIR: sdk-platform-java
           JOB_TYPE: install
+      - uses: actions/setup-go@v5
+        with:
+          go-version: 'stable'
+      - name: Install protoc
+        run: |
+          set -e
+          VERSION="33.2"
+          curl -fsSL --retry 5 --retry-delay 15 -o /tmp/protoc.zip "https://github.com/protocolbuffers/protobuf/releases/download/v$VERSION/protoc-$VERSION-linux-x86_64.zip"
+          cd /usr/local
+          sudo unzip -o /tmp/protoc.zip
+          protoc --version
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+          cache: 'pip'
+      - name: Install Librarian and tools
+        env:
+          PYTHONPATH: ${{ github.workspace }}/sdk-platform-java/hermetic_build/library_generation/owlbot
+        run: |
+          V=$(go run github.com/googleapis/librarian/cmd/librarian@latest config get version)
+          echo "Installing librarian version $V"
+          go install github.com/googleapis/librarian/cmd/librarian@$V
+          librarian install
+      - name: Setup Java 17 for Golden Tests
+        uses: actions/setup-java@v4
+        with:
+          java-version: 17
+          distribution: temurin
       - name: Showcase golden tests
         working-directory: java-showcase
         run: |
           mvn test \
             -P enable-golden-tests \
             --batch-mode \
             --no-transfer-progress
+      - name: Restore Matrix Java
+        uses: actions/setup-java@v4
+        with:
+          java-version: ${{ matrix.java }}
+          distribution: temurin
       - name: Parse showcase version
         working-directory: java-showcase/gapic-showcase
         run: echo "SHOWCASE_VERSION=$(mvn help:evaluate -Dexpression=gapic-showcase.version -q -DforceStdout)" >> "$GITHUB_ENV"