MFA with multiple tenants support

## MFA with multiple tenants support
**iOS**
Is not supported according to this documentation: https://firebase.google.com/docs/auth/ios/multi-factor
But registering a user on multi tenant, adding the phone 2FA, and logging in with the 2FA challenge fully works.

**Android**
Is not supported according to this documentation: https://firebase.google.com/docs/auth/android/multi-factor
But registering a user on multi tenant, adding the phone 2FA fully works.

Only logging in and doing the 2FA challenge fails with error:
>
[SmsRetrieverHelper] SMS verification code request failed: unknown status code: 17499 INVALID_PROJECT_ID:Project ID does not match MFA pending credential

The strange thing is that on Android, adding the 2FA works (the SMS with the verification code is sent, and verified correctly). but doing the login with 2FA challenge does not (which is essentially receiving a verification SMS again and verifying the code).
Essentially no new functionality is used in login versus registration so it should be easy to fix and fully support.

**Question:**
When can we expect official support of multi-tenancy 2FA on Android and iOS
And when can we expect (unofficial) support of multi-tenancy 2FA on Android (since unoficially it already works on iOS).