anchor.diff:      properties:
         blobstore:
           provider: gcs
  +        credentials_source: static
           json_key: |
             DIRECTOR-BLOBSTORE-SERVICE-ACCOUNT-FILE
           bucket_name: test-bosh-bucket
           encryption_key: BASE64-ENCODED-32-BYTES
         agent:
           blobstore:
  +          credentials_source: static
             json_key: |
               AGENT-SERVICE-ACCOUNT-BLOBSTORE-FILE
       ```
  
positive.code:     properties:
        blobstore:
          provider: gcs
          json_key: |
            DIRECTOR-BLOBSTORE-SERVICE-ACCOUNT-FILE
          bucket_name: test-bosh-bucket
          storage_class: REGIONAL
        agent:
          blobstore:
            json_key: |
              AGENT-SERVICE-ACCOUNT-BLOBSTORE-FILE
      ```
  
negative.code:     properties:
        blobstore:
          provider: gcs
          credentials_source: static
          json_key: |
            DIRECTOR-BLOBSTORE-SERVICE-ACCOUNT-FILE
          bucket_name: test-bosh-bucket
  