Popup a notification after logging in the captive portal network

Captive portal app will be auto dismissed after user login the
captive portal network. In order to improve the user experience,
popup a notification to notify user that the captive portal
network is connected.

Bug: 113629026
Test: 1.atest FrameworksNetTests:NetworkNotificationManagerTest
      2.Connect to a captive portal network and login, check if
      there is a notification popup.

Change-Id: Id54d12268e107af2f213c2bb348c5f7908e880f4
diff --git a/proto/src/system_messages.proto b/proto/src/system_messages.proto
index fba639c..8ee55e1 100644
--- a/proto/src/system_messages.proto
+++ b/proto/src/system_messages.proto
@@ -231,6 +231,8 @@
     NOTE_NETWORK_LOST_INTERNET = 742;
     // The system default network switched to a different network
     NOTE_NETWORK_SWITCH = 743;
+    // Device logged-in captive portal network successfully
+    NOTE_NETWORK_LOGGED_IN = 744;
 
     // Notify the user that their work profile has been deleted
     // Package: android