Update GHA versions

Author: fileformat

.github/workflows/appengine-deploy.yaml

@@ -12,16 +12,16 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v1
+        uses: actions/checkout@v2
 
       - name: GCloud auth
         id: 'auth'
-        uses: 'google-github-actions/auth@v0'
+        uses: 'google-github-actions/auth@v2'
         with:
           credentials_json: '${{ secrets.GCP_SA_KEY }}'
 
       - name: GCloud setup
-        uses: google-github-actions/setup-gcloud@v0
+        uses: google-github-actions/setup-gcloud@v2
 
       - name: Install yq
         run: sudo snap install yq