Keep approvals when rebasing through the UI with reset approvals on push enabled

Currently, reset approvals is predicated on three conditions:

If approvals are not zero which was true in your previous merge request
The option to reset approvals on push is enabled which is enabled
The rebase_commit_sha value of the merge is not the same as the head SHA of the branch.

Based on those conditions, UI-triggered rebase cannot be distinguished from pushes. We want to keep approvals when triggering rebase through the UI