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/wifi/CellularFallbackPreferenceController.java

@@ -22,6 +22,7 @@ import android.provider.Settings;
 import android.telephony.SubscriptionManager;
 
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.settings.R;
 import com.android.settings.core.TogglePreferenceController;
 
 /**
@@ -51,6 +52,11 @@ public class CellularFallbackPreferenceController extends TogglePreferenceContro
                 Settings.Global.NETWORK_AVOID_BAD_WIFI, isChecked ? "1" : null);
     }
 
+    @Override
+    public int getSliceHighlightMenuRes() {
+        return R.string.menu_key_network;
+    }
+
     private boolean avoidBadWifiConfig() {
         final int activeDataSubscriptionId = getActiveDataSubscriptionId();
         if (activeDataSubscriptionId == SubscriptionManager.INVALID_SUBSCRIPTION_ID) {