Switch to use addAuthenticatorsRegisteredCallback to get sensor props

Directly using getSensorPropertiesInternal to get fingerprint/face
sensor props is fine but may potentially have issues of race condition
or HAL taking too long to response during initialization.

Switch to use addAuthenticatorsRegisteredCallback which is safer. The
callback will be invoked immediately if sensor props are already
available, or invoked until registration of all sensors is done.

Fix: 266709333
Test: atest BinaryTransparencyServiceTest
Test: Mannually set the flag to true/false via:
      adb shell device_config put biometrics
          enable_biometric_property_verification true/false
      Then check whether data is logged via:
      m statsd_testdrive && statsd_testdrive 587
Change-Id: Ief69fe426e3beb8983e64032a845b7e5e3cf6c28