Add ability to show/hide individual settings in Sounds page.

This adds the following 7 new boolean flags:
config_show_alarm_volume
config_show_charging_sounds
config_show_media_volume
config_show_notification_ringtone
config_show_notification_volume
config_show_screen_locking_sounds
config_show_touch_sounds

Which when set to false, will hide the respective preferences in Sounds
page.

Bug: 69813881
Test: make RunSettingsRoboTests
ROBOTEST_FILTER=com.android.settings.notification all pass.

Change-Id: I84a2ce66b07c00d658422ce1a0eacaf9a01fae8a

tests/robotests/src/com/android/settings/notification/MediaVolumePreferenceControllerTest.java

@@ -27,30 +27,38 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
+import org.robolectric.RuntimeEnvironment;
 import org.robolectric.annotation.Config;
 
 import static com.google.common.truth.Truth.assertThat;
 
+import static org.mockito.Mockito.spy;
+
 @RunWith(SettingsRobolectricTestRunner.class)
 @Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
 public class MediaVolumePreferenceControllerTest {
 
-    @Mock
     private Context mContext;
-
     private MediaVolumePreferenceController mController;
 
     @Before
     public void setUp() {
         MockitoAnnotations.initMocks(this);
+        mContext = spy(RuntimeEnvironment.application);
         mController = new MediaVolumePreferenceController(mContext, null, null);
     }
 
     @Test
-    public void isAlwaysAvailable() {
+    public void isAvailable_byDefault_isTrue() {
         assertThat(mController.isAvailable()).isTrue();
     }
 
+    @Test
+    @Config(qualifiers = "mcc999")
+    public void isAvailable_whenNotVisible_isFalse() {
+        assertThat(mController.isAvailable()).isFalse();
+    }
+
     @Test
     public void getAudioStream_shouldReturnMusic() {
         assertThat(mController.getAudioStream()).isEqualTo(AudioManager.STREAM_MUSIC);