Consolidate fingerprint overlay controllers.

Prevent duplication in side/udfps sensor handling for common
operations (i.e. show, hide) and remove static boilerplater helpers.

Bug: 197265282
Test: atest SensorOverlaysTest
Test: atest com.android.systemui.biometrics
Change-Id: I9a5bad5d19f044f4292eeda1ae666cf5b807f7eb