Update UI to inform user that container registry cleanup policies are available

Context

This issue came from https://gitlab.com/gitlab-org/gitlab/-/issues/262639#note_858991307 where @10io highlighted that we currently show a banner to inform users that container registry cleanup policies are available:

Banners are good for communicating something that is high priority, such as introducing a new feature. However, for the long term, we can signal that cleanup policies are available in a more subtle way.

In testing Package cleanup policies, the following treatment tested well:

Proposal ⬇

See attached design