Provide isUserInLockdown through BiometricSettingsRepository

Since LockPatternUtils.registerStrongAuthTracker is a binder based listener,
this CL changes BiometricSettingsRepository#isStrongBiometricAllowed to rely on the same listener we register for isUserInLockdown

Bug: 262838215
Test: atest BiometricSettingsRepositoryTest
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:231b255ae166743b1834bf3c105f0b88e39cdcb3)
Merged-In: If9cb20ce12d2aa6ace5a1a5ccce2b887bdfa6e44
Change-Id: If9cb20ce12d2aa6ace5a1a5ccce2b887bdfa6e44