[Provider Model] Internet Picker implementation.

Show mobile network on internet page

 With mobile network
  - https://screenshot.googleplex.com/7HzGhnbpitErynY

 Without mobile network
  - https://screenshot.googleplex.com/8sNVggTpKEhKeRh

Class diff: https://diff.googleplex.com/#key=WosyTF0ANVMf

Doc: https://docs.google.com/presentation/d/1azrZVS54pxM2lt9LkZHtFh_6W3fyDw_kTTPVQ_mJCi4/edit#slide=id.g9c7123c172_0_448

Bug: 173105859
Test: atest NetworkMobileProviderControllerTest passed
Test: make RunSettingsRoboTests ROBOTEST_FILTER=SubscriptionsPreferenceControllerTest passed

Change-Id: I9671a0b85aad1dd2f53772539505b0ad96edbda3

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

@@ -41,6 +41,7 @@ import androidx.preference.PreferenceGroup;
 import androidx.preference.PreferenceScreen;
 
 import com.android.settings.R;
+import com.android.settings.Utils;
 import com.android.settings.network.telephony.DataConnectivityListener;
 import com.android.settings.network.telephony.MobileNetworkActivity;
 import com.android.settings.network.telephony.MobileNetworkUtils;
@@ -77,7 +78,6 @@ public class SubscriptionsPreferenceController extends AbstractPreferenceControl
     // Map of subscription id to Preference
     private Map<Integer, Preference> mSubscriptionPreferences;
     private int mStartOrder;
-
     /**
      * This interface lets a parent of this class know that some change happened - this could
      * either be because overall availability changed, or because we've added/removed/updated some
@@ -291,7 +291,7 @@ public class SubscriptionsPreferenceController extends AbstractPreferenceControl
                 // subscriptions with same group UUID.
                 .filter(subInfo ->
                         isSubscriptionCanBeDisplayed(mContext, subInfo.getSubscriptionId()))
-                .count() >= 2;
+                .count() >= (Utils.isProviderModelEnabled(mContext) ? 1 : 2);
     }
 
     @Override