Cannot enroll phone other than the verified phone when using SMS MFA

[Dozer1170]

Describe the bug
There is no way to enroll a different phone number after you enroll a first phone number in SMS MFA. There is an updatePhone flag that needs to be sent up as a query param on the SMS MFA call.

To Reproduce
Steps to reproduce the behavior:

1. Enroll phone 1 in SMS MFA
2. Reset the SMS MFA
3. Enroll phone 2 in SMS MFA
4. Get error saying that the account already has a verified phone (not exact text, but similar)

Expected behavior
You can choose whether or not you would like to update the verified phone when enrolling SMS MFA.

Smartphone (please complete the following information):

• Device: [e.g. iPhone 11]
• OS: iOS13
• Browser: Safari

Additional context
I have created a pull request to allow updating the phone on an SMS enroll request.
#112