Convert biometrics to RestrictedPreference

Bug: 188847063
Test: adb shell settings put secure com.android.settings.biometrics.ParentalControlsUtils.always_require_consent 1
      Preference becomes gray with an info icon
Test: atest ParentalControlsUtilsTest
Test: make -j56 RunSettingsRoboTests ROBOTEST_FILTER=CombinedBiometricStatusPreferenceControllerTest
Test: make -j56 RunSettingsRoboTests ROBOTEST_FILTER=FingerprintStatusPreferenceControllerTest
Test: make -j56 RunSettingsRoboTests ROBOTEST_FILTER=FaceStatusPreferenceControllerTest

Change-Id: I929c11606eec76063f7b060fdc5cb2b5f60a80e2