Doing some improvement for stability: 1. Check hasSystemFeature(PackageManager.FEATURE_FACE) for non-face service devices. 2. Wrap addAuthenticatorsRegisteredCallback() 3. Find mPreference before addAuthenticatorsRegisteredCallback Bug: 276680407 Bug: 278174667 Bug: 277647959 Bug: 277725506 Test: m RunSettingsRoboTests -j30 ROBOTEST_FILTER= \ FaceSettingsFooterPreferenceControllerTest (cherry picked from https://googleplex-android-review.googlesource.com/q/commit:e85d588904e549d2eadd249ba0a03acfb2b02382) Merged-In: I81346b6eb8c44106c5e52867d69c8736203dd558 Change-Id: I81346b6eb8c44106c5e52867d69c8736203dd558