Fix giant loader in Container Registry expiration policy settings

Due to !22992 (merged) not yet being ready the Container Registry expiration policy form need to be removed from the page and placed back.

To somehow mitigate the bounce of the page we now have a very big spinning loader, this is not really optimal.

As soon as !22992 (merged) is merged we need to refactor the UI to display a smaller loader overlayed on top of the form.