Merge changes from topic "clientmonitor-cleanup3"

* changes:
  Clear identity when checking BiometricService#isStrongBiometric()
  17/n: Make generateChallenge/revokeChallenge ClientMonitors
  16/n: Introduce ClientMonitor#FinishCallback
  15/n: Combine EnumerateClient into InternalEnumerateClient
  14/n: Remove the use of groupId
  13/n: Remove the use of DaemonWrapper