message: Treat forbidden on head as not found
diff: @@ -107,7 +107,9 @@ export class CloudStorage implements Storage {
  contentEncoding: ContentEncoding,
  };
  } catch (err) {
  - if (err.code === 'NotFound' || err.code === 'NoSuchKey') {
  + // Since the credentials given do not have ListBucket permissions, we get a Forbidden error
  + // on missing objects
  + if (err.code === 'NotFound' || err.code === 'NoSuchKey' || err.code === 'Forbidden') {
  return undefined;
  }
  throw err;
  