Fix a memory leak in ConnectivityManager.

Remove callbacks from the internal storage when they are being unregistered.

Change-Id: Ia42ed7aefaebd8caf3eada8e42b6cb7a940d7647

core/java/android/net/ConnectivityManager.java

@@ -2734,7 +2734,7 @@ public class ConnectivityManager {
     private void incCallbackHandlerRefCount() {
         synchronized(sCallbackRefCount) {
             if (sCallbackRefCount.incrementAndGet() == 1) {
-                // TODO - switch this over to a ManagerThread or expire it when done
+                // TODO: switch this to ConnectivityThread
                 HandlerThread callbackThread = new HandlerThread("ConnectivityManager");
                 callbackThread.start();
                 sCallbackHandler = new CallbackHandler(callbackThread.getLooper(),
@@ -3093,6 +3093,10 @@ public class ConnectivityManager {
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
+
+        synchronized (sNetworkCallback) {
+            sNetworkCallback.remove(networkCallback.networkRequest);
+        }
     }
 
     /**