[Settings] Fix behavior of mobile data plan

Fix UI issue.

Bug: 150352656
Test: make
Change-Id: If5c6fc3c07259c45eba4d0f1f76b7b6de20cc6f4

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

@@ -85,6 +85,7 @@ public class MobilePlanPreferenceController extends AbstractPreferenceController
         if (mHost != null && KEY_MANAGE_MOBILE_PLAN.equals(preference.getKey())) {
             mMobilePlanDialogMessage = null;
             onManageMobilePlanClick();
+            return true;
         }
         return false;
     }