[Large screen] Shows MobileNetworkActivity in 2-pane

MobileNetworkActivity has launchMode singleTask, it makes
the Activity shows in full screen instead of 2-pane.

This change register SplitPairRule for the Activity to show
in 2-pane. However, there are other objects which starts
MobileNetworkActivity, it still needs later CL to refine
and register SplitPairRule for other objects which starts
MobileNetworkActivity.

Bug: 204039043
Test: manual
      Settings -> Network & Internet -> SIMs
Change-Id: Ia15c17c88efd46c5bb2b41aa21848293b9ff5610

src/com/android/settings/network/MobileNetworkSummaryController.java

@@ -33,9 +33,9 @@ import androidx.preference.Preference;
 import androidx.preference.PreferenceScreen;
 
 import com.android.settings.R;
+import com.android.settings.activityembedding.ActivityEmbeddingRulesController;
 import com.android.settings.core.PreferenceControllerMixin;
 import com.android.settings.dashboard.DashboardFragment;
-import com.android.settings.network.helper.SelectableSubscriptions;
 import com.android.settings.network.helper.SubscriptionAnnotation;
 import com.android.settings.network.telephony.MobileNetworkActivity;
 import com.android.settings.overlay.FeatureFactory;
@@ -202,6 +202,12 @@ public class MobileNetworkSummaryController extends AbstractPreferenceController
                         || mStatusCache.isPhysicalSimDisableSupport()) {
                     final Intent intent = new Intent(mContext, MobileNetworkActivity.class);
                     intent.putExtra(Settings.EXTRA_SUB_ID, info.getSubscriptionId());
+                    //  MobilenetworkActivity is singleTask, set SplitPairRule to show in 2-pane.
+                    ActivityEmbeddingRulesController.registerTwoPanePairRuleForSettingsHome(
+                            mContext,
+                            intent.getComponent(),
+                            null /* secondaryIntentAction */,
+                            false /* clearTop */);
                     mContext.startActivity(intent);
                     return true;
                 }