Add highlight menu keys for all toggle pref controllers and custom slices

Bug: 204695404
Test: manual, robotest build pass, unit
Change-Id: Iad2e28ada8ddb766ffa7eff2c8dc581250cbd6f8

src/com/android/settings/notification/VolumeSeekBarPreferenceController.java

@@ -23,6 +23,7 @@ import androidx.lifecycle.LifecycleObserver;
 import androidx.lifecycle.OnLifecycleEvent;
 import androidx.preference.PreferenceScreen;
 
+import com.android.settings.R;
 import com.android.settings.notification.VolumeSeekBarPreference.Callback;
 import com.android.settingslib.core.lifecycle.Lifecycle;
 
@@ -75,6 +76,11 @@ public abstract class VolumeSeekBarPreferenceController extends
         }
     }
 
+    @Override
+    public int getSliceHighlightMenuRes() {
+        return R.string.menu_key_sound;
+    }
+
     @Override
     public int getSliderPosition() {
         if (mPreference != null) {