Combined biometric settings implementation

There will be multiple biometrics authentications existing at the same
time, so we added a new page for multiple biometrics to control
biometrics settings.

Bug: 183449119
Test: manual test
Change-Id: I359082caf771e07dfd5b24973cb8a3cf372c1b30

src/com/android/settings/biometrics/face/FaceSettingsKeyguardPreferenceController.java

@@ -70,7 +70,8 @@ public class FaceSettingsKeyguardPreferenceController extends FaceSettingsPrefer
 
     @Override
     public int getAvailabilityStatus() {
-        return AVAILABLE;
+        // When the device supports multiple biometrics auth, this preference will be unavailable.
+        return Utils.isMultipleBiometricsSupported(mContext) ? UNSUPPORTED_ON_DEVICE : AVAILABLE;
     }
 
     @Override