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/network/AirplaneModePreferenceController.java

@@ -120,6 +120,11 @@ public class AirplaneModePreferenceController extends TogglePreferenceController
         return isAvailable(mContext) ? AVAILABLE : UNSUPPORTED_ON_DEVICE;
     }
 
+    @Override
+    public int getSliceHighlightMenuRes() {
+        return R.string.menu_key_network;
+    }
+
     @Override
     public void onStart() {
         if (isAvailable()) {