message: When skip_gce_check is set to "true", log the message about missing bearer token at INFO instead of WARNING, since skipping the GCE check most often means that we are accessing public objects.
diff: @@ -176,12 +176,19 @@ Status GoogleAuthProvider::GetToken(string* t) {
  return Status::OK();
  }
  + if (skip_gce_check) {
  + LOG(INFO)
  + << "Attempting an empty bearer token since no token was retrieved "
  + << "from files, and GCE metadata check was skipped.";
  + } else {
  LOG(WARNING)
  << "All attempts to get a Google authentication bearer token failed, "
  - << "returning an empty token. Retrieving token from files failed with \""
  + << "returning an empty token. Retrieving token from files failed with "
  + "\""
  << token_from_files_status.ToString() << "\"."
  << " Retrieving token from GCE failed with \""
  << token_from_gce_status.ToString() << "\".";
  + }
  // Public objects can still be accessed with an empty bearer token,
  // so return an empty token instead of failing.
  