[Settings] Sync summary of call preference with dialer

Replacing the display of summary part within Settings' calls preference
by VoIP account when configured calling account settings within Dialer.

The click behavior for calls preference remain unchanged, due to this is
the configuration for subscription (instead of for all kinds of
accounts).

Bug: 136277187
Test: manual
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=DefaultSubscriptionControllerTest
Merged-In: Iaa5fa1f3efe7ba2463caa0b450077f885d42b1c8
Change-Id: I6f2f44d305119f09e2188de702f14f2506a4903c

src/com/android/settings/network/telephony/SmsDefaultSubscriptionController.java

@@ -17,6 +17,7 @@
 package com.android.settings.network.telephony;
 
 import android.content.Context;
+import android.telecom.PhoneAccountHandle;
 import android.telephony.SubscriptionInfo;
 import android.telephony.SubscriptionManager;
 
@@ -40,4 +41,10 @@ public class SmsDefaultSubscriptionController extends DefaultSubscriptionControl
     protected void setDefaultSubscription(int subscriptionId) {
         mManager.setDefaultSmsSubId(subscriptionId);
     }
+
+    @Override
+    public PhoneAccountHandle getDefaultCallingAccountHandle() {
+        // Not supporting calling account override by VoIP
+        return null;
+    }
 }