Refine get props inside FingerprintRepository

FingerprintManager::getSensorPropertiesInternal() might return an
incorrect value if it's done too soon. Change to use
FingerprintManager::addAuthenticatorsRegisteredCallback() in
FingerprintRepository.

Bug: 264827022
Test: atest FingerprintRepositoryTest
      FingerprintEnrollIntroViewModelTest
      FingerprintEnrollmentViewModelTest
Change-Id: I68dd3ec1182662cc55aaa8be77a62245ab29cd54