Protected Environment Approvals cannot be edited to 0

Summary

Customer reported (internal link) the following behavior:

when you create a protected environment you can select 0 as an option for required approvals but if you accidently select one you can not update to 0

I duplicated this myself. If a protected environment already exists with 0 as the number of required approvals and you edit this to any number in the dropdown, you cannot edit it back to 0. Workaround: delete the protected environment and recreate it.

Steps to reproduce

1. Follow the steps to create a protected group here, and set the number of required approvals to 0. Save.
2. Attempt to edit the number of required approvals, notice the dropdown list starts at 1.
3. Since it autosaves, if you click on any of those numbers, you cannot now change it back to 0 without deleting and recreating the protected environment.

What is the current bug behavior?

Users can create protected environments with 0 required approvers, but cannot edit the number of required approvers to 0.

What is the expected correct behavior?

Either users should not be able to create a protected environment with 0 required approvers, or they should be able to edit the number of required approvers to 0.

Relevant logs and/or screenshots

Screenshots: