Add Container Registry on/off status to admin area

What does this MR do?

Display an on/off icon under the "Features" section of the admin area for the Container Registry.

Are there points in the code the reviewer needs to double check?

I couldn't find any existing tests for the admin dashboard. Reviewers, let me know if you think we should add some :)

Why was this MR needed?

The GitLab Admin area displays on/off status for most features but not GitLab Container Registry.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• CHANGELOG entry added
• [-] Documentation created/updated
• [-] API support added
• Tests
  • [-] Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if you do - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #22805 (closed)