Unable to remove default approvers that were set in project settings on merge request

Summary

When Can override approvers and approvals required per merge request is enabled, I am unable to remove the default approver as set in the project settings. I am also unable to set the number of approvals lower than what is set in the project settings.

Steps to reproduce

1. Enable Can override approvers and approvals required per merge request in the project settings
2. Have a user create a merge request and attempt to remove the default approver. Additionally, when trying to set the number of approvals to 0, a message is displayed that says Value must be equal to or greater than 1. (I have 1 set for the number of approvals required in the project settings). Found this as a restriction in the documenation.

What is the current bug behavior?

Cannot remove the default project approval requirements on a merge request. However, you can add your own approver.

What is the expected correct behavior?

You should be able to remove the default approver and choose a lower number of required approvals than those set in the project settings.

Customer ticket: https://gitlab.zendesk.com/agent/tickets/122174 (internal use)

Customer is running 11.8. I was able to reproduce on 11.10