Add support for ci_secure_files to consolidated object storage

Originally raised in gitlab-org/incubation-engineering/mobile-devops/readme#124 (closed), the purpose of this issue is to track the change to add support for ci_secure_files to consolidated object storage as part of the %17.0 release.

This is considered a breaking change since it will require self-managed customers using consolidated object storage to create a new object storage bucket during the upgrade process.