Update BiometricUnlockController for secure lock device

Delays face authenticated signal, because device should not be
considered unlocked until face auth is confirmed by the user on the UI

Flag: android.security.secure_lock_device
Bug: 401645997
Bug: 427071518
Test: atest BiometricsUnlockControllerTest
Change-Id: Iace77ffb5734c99bcd400a9907bfde836b459acd