Validation to prevent default project, group visibility being restricted

What does this MR do and why?

Related to #415524 (closed), on SaaS, user registration go through the Create or import your first project page, when either one of the default_group_visibility and default_project_visibility is restricted, user sees the following errors:

Can not create group	Can not create project

Screenshots or screen recordings

• Example setting that triggers the validation error

• Validation error message

How to set up and validate locally

1. Simulate SaaS
2. Turn on the feature flag by going to rails console and run Feature.enable(:prevent_visibility_restriction)
3. Log in as admin
4. Go to /admin/application_settings/general#js-visibility-settings
5. Select Internal under Default group visibility
6. Check Internal under Restricted visibility levels
7. Submit the form

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.