R1:7805b217ad8b

Prevent users from editing, disabling, or swapping their primary contact number while they have SMS MFA

Summary:
Depends on D20022. Ref T13222. Since you can easily lock yourself out of your account by swapping to a bad number, prevent contact number edits while "contact number" MFA (today, always SMS) is enabled.

(Another approach would be to bind factors to specific contact numbers, and then prevent that number from being edited or disabled while SMS MFA was attached to it. However, I think that's a…