Bump actions/checkout and subosito/flutter-action versions

Author: JeroenWeener

.github/workflows/google_api_availability.yaml

@@ -27,10 +27,10 @@ jobs:
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       # Make sure the stable version of Flutter is available
-      - uses: subosito/flutter-action@v1
+      - uses: subosito/flutter-action@v2
         with:
           channel: 'stable'