Avoid error when canceling google signin

[diedu89]

Currently if user cancel signin with google an error is shown as a toast instead of the message of user cancellation #1404, to avoid this play-services-auth is upgraded
Also the handle of the error code 12501 is added in order to set an UserCancellationException instead of FirebaseUiException

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[diedu89]

I signed it

[googlebot]

CLAs look good, thanks!

[SUPERCILEX]

LGTM with the styling fixed

[samtstern]

@diedu89 thank you!

[samtstern]

Merged into the 4.2.0 development branch