24/n: Use lazy retrieval for HAL

Instead of passing it in through ClientMonitor#start, which causes
whatever is scheduling the ClientMonitors to require knowledge of
the HAL type, make it a parameter in the constructor that allows for
lazy retrieval.

1) Reminder that we should always retrieve a fresh pointer to the
   HAL, in case it crashed previously, or is stale, or was never
   loaded, etc. This functionality is preserved
2) As mentioned above, this allows the scheduler to remain agnostic
   of HAL type

Bug: 157790417

Test: Enroll, auth for fingerprint/face devices
Change-Id: Ib61cfecec17dc2b33937e089bdb9777f50e7a836