The normal solution for something like this would be to have 3 service accounts (development-app, staging-app, production-app), each of which would have its own set of credentials and permissions. You could either have a test, staging, and production project, or you could just have test, staging, and production buckets within a single project. You can create a whole range of per-project service accounts, each with its own set of credentials and permissions.
Unfortunately, interoperable storage access keys are not available for service accounts, only regular Google user accounts. In order to do what you want, you'd need to have three user accounts, each of which was granted access to exactly one of those buckets.