Allow NetworkRequest release from the system process.

Otherwise attempts to release that are triggered by the binder death
receipient will be rejected.

Bug: 17187437
Change-Id: If3924d82dba69c572708e04c11d17ed25ae6870d

services/core/java/com/android/server/ConnectivityService.java

@@ -2160,7 +2160,7 @@ public class ConnectivityService extends IConnectivityManager.Stub {
     private void handleReleaseNetworkRequest(NetworkRequest request, int callingUid) {
         NetworkRequestInfo nri = mNetworkRequests.get(request);
         if (nri != null) {
-            if (nri.mUid != callingUid) {
+            if (Process.SYSTEM_UID != callingUid && nri.mUid != callingUid) {
                 if (DBG) log("Attempt to release unowned NetworkRequest " + request);
                 return;
             }