Logstash s3 output using role_arn in GCP

Related to a question I asked earlier relating to uploading log files from a LogStash Instance running on GCP to an s3 bucket. Is it possible to do using role_arn? Most use cases of role_arn involve the running of a LogStash instance in an ec2 instance in which the role has been attached to the instance. Which is not the case in this scenario. Would the alternative be to use a Google cloud storage instead of an s3