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/gestures/OneHandedMainSwitchPreferenceController.java

@@ -21,6 +21,7 @@ import android.net.Uri;
 
 import androidx.preference.PreferenceScreen;
 
+import com.android.settings.R;
 import com.android.settings.widget.SettingsMainSwitchPreferenceController;
 import com.android.settingslib.core.lifecycle.LifecycleObserver;
 import com.android.settingslib.core.lifecycle.events.OnStart;
@@ -92,4 +93,9 @@ public class OneHandedMainSwitchPreferenceController extends
             mPreference.setChecked(isChecked());
         }
     }
+
+    @Override
+    public int getSliceHighlightMenuRes() {
+        return R.string.menu_key_system;
+    }
 }