Draft: Keep user on same page when modifying feature flag

What does this MR do and why?

Proof of concept for keeping users on the same feature flag page when they hit Save Changes

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.

Related to #390611