Disable setting if sensor is convenience.

This change disables the FaceSettings Confirmation setting if a
sensor is convenience. This is due to the fact that convenience strength
sensors can't be used by BiometricPrompt (so this setting has no
effect.)

Test: Verified this setting shows depending on whether or not the sensor
is convenience or not.
Fixes: 204137656

Change-Id: I88daf9f12b76d06697275161385f463fb88e0f3a

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

@@ -19,13 +19,17 @@ package com.android.settings.biometrics.face;
 import static android.provider.Settings.Secure.FACE_UNLOCK_ALWAYS_REQUIRE_CONFIRMATION;
 
 import android.content.Context;
+import android.hardware.biometrics.SensorProperties;
 import android.hardware.face.FaceManager;
+import android.hardware.face.FaceSensorProperties;
 import android.provider.Settings;
 
 import androidx.preference.Preference;
 
 import com.android.settings.Utils;
 
+import java.util.List;
+
 /**
  * Preference controller giving the user an option to always require confirmation.
  */
@@ -75,6 +79,14 @@ public class FaceSettingsConfirmPreferenceController extends FaceSettingsPrefere
 
     @Override
     public int getAvailabilityStatus() {
-        return AVAILABLE;
+        List<FaceSensorProperties> properties = mFaceManager.getSensorProperties();
+        // If a sensor is convenience, it is possible that it becomes weak or strong with
+        // an update. For this reason, the sensor is conditionally unavailable.
+        if (!properties.isEmpty()
+                && properties.get(0).getSensorStrength() == SensorProperties.STRENGTH_CONVENIENCE) {
+            return CONDITIONALLY_UNAVAILABLE;
+        } else {
+            return AVAILABLE;
+        }
     }
 }