Move fingerprint authentication to a sidecar

It's possible for this sequence of events to occur
1) touch FPS
2) rotate device
3) authentication succeed message goes to pre-rotated activity
The pre-rotated activity will continue authenticating, and the fragment
will not highlight correctly upon authentication

Fixes: 63907591

Test: manual test of above condition, looks to be fixed

Test: rapidly tapping FPS while rotating works as expected

Change-Id: Ic830016f8bf52f926681110fcd908619ffc9dd31