Uninformative error when GATK doesn't have permission to check whether a GCS bucket is Requester Pays

[droazen]

Currently, if the GATK doesn't have permission to check whether a GCS bucket is Requester Pays (which is a separate permission from access to the bucket itself!), we get a cryptic error message along the lines of:

User does not have storage.buckets.get access to bucket_name

This is the same error the gsutil client gives in the same situation:

$ gsutil requesterpays get gs://gatk-best-practices
AccessDeniedException: 403 [email protected] does not have storage.buckets.get access to gatk-best-practices.

Ideally we should detect this situation upfront in the GATK and emit a more informative error message.