6/n: Key by Biometric ID instead of Modality

This change contains the following major changes:
1) Moves checkAndGetAuthenticators and most of its logic into
   a new modular class (PreAuthInfo), which has takes API parameters,
   biometric sensor status, user/system settings, etc and generates
   preliminary info for client requests (canAuthenticate
   authenticate APIs).
2) Sensor state during authentication sessions are now tracked
   within BiometricSensor (used to be floating around in
   BiometricService)
3) BiometricPrompt (above system server) is responsible for
   handling any combination of modality errors now. As such,
   updated selection logic and also added a catch-all string

Bug: 149067920

Test: atest com.android.server.biometrics
Test: CtsVerifier biometric section on face and fingerprint devices

Change-Id: I030593de2c350824bc961f92a75895f49a9c7996