title: Issue with connecting Golang application on Cloud Run with Firestore
body: <p>I try to get all Documents from Firestore using the below function. </p>
  
  <p>The credentials are stored in an encrypted file in a GCP Cloud Source repository. 
  I decrypted the configuration in the Cloud Build trigger and set the ENV in the Dockerfile pointing to the file. I see the content by RUN ls /app/credentials.json.</p>
  
  <p>The error I get in the application log:
  rpc error: code = Unavailable desc = all SubConns are in TransientFailure, latest connection error: connection error: desc = "transport: authentication handshake failed: x509: certificate signed by unknown authority"</p>
  
  <p>The credentials are stored in an encrypted file in a GCP Cloud Source repository. 
  I decrypted the configuration in the Cloud Build trigger and set the ENV in the Dockerfile pointing to the file. I see the content by RUN ls /app/credentials.json.</p>
  
  <p>The error I get in the application log:
  <code>rpc error: code = Unavailable desc = all SubConns are in TransientFailure, latest connection error: connection error: desc = "transport: authentication handshake failed: x509: certificate signed by unknown authority"</code></p>