Replace generic checkbox with GitLab UI styled checkbox in app/views/admin/application_settings/_registry.html.haml

What does this MR do and why?

The MR updates generic checkbox element to GitLab UI styled checkbox on the Admin -> Settings -> CI/CD page, Container Registry section.

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. In gdk.yml enable the container registry

   registry:
      enabled: true

2. Visit Admin -> Settings -> CI/CD page
3. Visit any group or project member pages such as http://127.0.0.1:3000/groups/flightjs/-/group_members
4. Select Container Registry section

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Review progress:

• UX review
• backend developer review
• backend maintainer review
• frontend developer review
• frontend maintainer review
• test Quality review

Related to #358305 (closed)