Request Thread network at the initialize()

Currently requestThreadNetwork is called in registerThreadNetwork. This creates a new NetworkCallback for Thread every time when Thread is turned on. We'd better just use one callback to avoid potential issues.

Bug: 319179354

Change-Id: I96bad351f089b32a9acd919dea2e2b6b2aea68d2

thread/service/java/com/android/server/thread/ThreadNetworkControllerService.java

@@ -333,6 +333,7 @@ final class ThreadNetworkControllerService extends IThreadNetworkController.Stub
                     mLinkProperties.setMtu(TunInterfaceController.MTU);
                     mConnectivityManager.registerNetworkProvider(mNetworkProvider);
                     requestUpstreamNetwork();
+                    requestThreadNetwork();
 
                     initializeOtDaemon();
                 });
@@ -413,9 +414,10 @@ final class ThreadNetworkControllerService extends IThreadNetworkController.Stub
     private void requestThreadNetwork() {
         mConnectivityManager.registerNetworkCallback(
                 new NetworkRequest.Builder()
+                        // clearCapabilities() is needed to remove forbidden capabilities and UID
+                        // requirement.
                         .clearCapabilities()
                         .addTransportType(NetworkCapabilities.TRANSPORT_THREAD)
-                        .removeForbiddenCapability(NetworkCapabilities.NET_CAPABILITY_LOCAL_NETWORK)
                         .build(),
                 new ThreadNetworkCallback(),
                 mHandler);
@@ -459,8 +461,6 @@ final class ThreadNetworkControllerService extends IThreadNetworkController.Stub
             return;
         }
 
-        requestThreadNetwork();
-
         mNetworkAgent = newNetworkAgent();
         mNetworkAgent.register();
         mNetworkAgent.markConnected();