stage and prod functions error (default credentials missing)

[apilly]

Though the stage and prod are working with no issue, functions after latest deployment throws below error:

Error: Could not load the default credentials. Browse to https://cloud.google.com/docs/authentication/getting-started  for more information.
at GoogleAuth.getApplicationDefaultAsync (/workspace/node_modules/google-auth-library/build/src/auth/googleauth.js:160:19)
at processTicksAndRejections (internal/process/task_queues.js:95:5)
at async GoogleAuth.getClient (/workspace/node_modules/google-auth-library/build/src/auth/googleauth.js:502:17)
at async GrpcClient._getCredentials (/workspace/node_modules/google-gax/build/src/grpc.js:92:24)
at async GrpcClient.createStub (/workspace/node_modules/google-gax/build/src/grpc.js:213:23)

reason could be difference in Firebase version used to deploy the latest change v8.6.5 vs v5.9.0 used in production. We can find more info in this article https://stackoverflow.com/a/58409339. Apparently this needs a code change in the way we are fetching the default creds for newer firebase versions. Jira story request for deployment.