Handle null intent in WifiCallingPreferenceController

When intent is null, we will hide wifi calling preference however
its listener might still triggered with null intent.

This CL update controller so it can handle this event inside listener
callback.

Fixes: 135095929
Test: RunSettingsRoboTests
Change-Id: I4c5aba03871f11a2d9f9b4da329c2c2655ff9adb

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

@@ -114,6 +114,10 @@ public class WifiCallingPreferenceController extends TelephonyBasePreferenceCont
         if (mSimCallManager != null) {
             Intent intent = MobileNetworkUtils.buildPhoneAccountConfigureIntent(mContext,
                     mSimCallManager);
+            if (intent == null) {
+                // Do nothing in this case since preference is invisible
+                return;
+            }
             final PackageManager pm = mContext.getPackageManager();
             List<ResolveInfo> resolutions = pm.queryIntentActivities(intent, 0);
             preference.setTitle(resolutions.get(0).loadLabel(pm));