Add BiometricPromptService

The change introduces the following:
  - BiometricPrompt communicatates with BiometricPromptService (new)
    system service. The service does the decision making for which
    biometric modality to use.
  - As a result, a lot of logic is moved from <Biometric>Manager
    to BiometricPrompt. FingerprintManager now does not care about
    BiometricPrompt logic anymore (reverts several P changes).

Face, and all future <Biometric>Service interfaces must be protected by
the signature-only MANAGE_BIOMETRIC permission. Settings, SystemUI, and
BiometricPromptService are their only clients.

Bug: 72825012

Test: BiometricPromptDemo works
Test: Keyguard works
Test: Settings works

Change-Id: I2b7d6eff81bc07950202c50e592d733032523bf0