[firebase_auth] updateCurrentUser method missing from API

[olof-dev]

The updateCurrentUser method of the Firebase Auth API appears to be missing from the Flutter implementation. This method would for example be useful for resetting to an anonymous user if a problem was encountered during a subsequent sign-in. For example, in the flow anonymous user --> linkWithCredential --> credential-already-in-use, the natural flow (as in the docs at https://firebase.google.com/docs/auth/android/account-linking#java_4 ) would be to sign in with the credentials via signInWithCredential and attempt to merge the two users. If merging were to fail for some reason, I'd want to be able to reset state to being as it was before the sign-in, ie return to the anonymous user. I think (but am not sure, as I only use Firebase via Flutter) that updateCurrentUser would allow for this.

In the Android API ref:
https://firebase.google.com/docs/reference/android/com/google/firebase/auth/FirebaseAuth#updateCurrentUser(com.google.firebase.auth.FirebaseUser)

Would it be possible to get this method into Flutter Firebase API?