code: public Acl createBucketAcl(String bucketName) {
      // [START createBucketAcl]
      Acl acl = storage.createAcl(bucketName, Acl.of(User.ofAllAuthenticatedUsers(), Role.READER));
      // [END createBucketAcl]
      return acl;
    }
docs: [VARIABLE "my_unique_bucket"]