Add virtual Face HAL

Fixes: 230514750
Test: atest VtsHalBiometricsFaceTargetTest
Test: atest VtsHalBiometricsFingerprintTargetTest
Test: atest android.hardware.biometrics.face.FakeFaceEngineTest
Test: atest android.hardware.biometrics.face.FakeFingerprintEngineTest
Test: See README.md
Test: Verified that face and fingerprint get reset upon authenticating.

Change-Id: I57c1a61bec960e3be28736e6050be662ef412d8c