Migrate to the new GCP action for setting up gcloud. (#5198)

Author: yifanyang

.github/workflows/health-metrics-test.yml

@@ -18,7 +18,7 @@ jobs:
       - uses: actions/setup-node@v2
         with:
           node-version: 14.x
-      - uses: GoogleCloudPlatform/github-actions/setup-gcloud@master
+      - uses: google-github-actions/setup-gcloud@master
         with:
           service_account_key: ${{ secrets.GCP_SA_KEY }}
       - run: yarn install
@@ -34,7 +34,7 @@ jobs:
       - uses: actions/setup-node@v2
         with:
           node-version: 14.x
-      - uses: GoogleCloudPlatform/github-actions/setup-gcloud@master
+      - uses: google-github-actions/setup-gcloud@master
         with:
           service_account_key: ${{ secrets.GCP_SA_KEY }}
       - run: yarn install