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/display/ControlsPrivacyPreferenceController.java

@@ -70,6 +70,11 @@ public class ControlsPrivacyPreferenceController extends TogglePreferenceControl
         refreshSummary(preference);
     }
 
+    @Override
+    public int getSliceHighlightMenuRes() {
+        return R.string.menu_key_display;
+    }
+
     private boolean isEnabled() {
         return isControlsAvailable();
     }