It consists of two parts:
1. Redirecting users to the configured external storage
1. Allowing the external storage to request the static object(s)
on behalf of the user by means of specific tokens
Part of https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/6829
Was introduced in the time that GitLab still used NFS, which is not
required anymore in most cases. By removing this, the API it calls will
return empty responses. This interface has to be removed in the next
major release, expected to be 12.0.