Implement client monitors for face AIDL

This CL implements all of the monitors except for FaceGetFeatureClient
and FaceSetFeatureClient because the get/set feature methods aren't
currently supported in the AIDL interface.

Bug: 171335732
Test: build
Change-Id: Ib6eaff5d7a323b8e9333ca8408ec69f488108a31
10 files changed