When adding a NetworkRequest, cancel linger for satisfying Network.

This fixes a problem where a requested network can later suddenly disappear if
it was lingering when the request arrived and later the linger timeout expired.

bug:15927234
Change-Id: Ib3fae45820ce4421e3bc5b623937a16d5f1efa0f

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

@@ -3332,6 +3332,12 @@ public class ConnectivityService extends IConnectivityManager.Stub {
         }
         if (bestNetwork != null) {
             if (VDBG) log("using " + bestNetwork.name());
+            if (nri.isRequest && bestNetwork.networkInfo.isConnected()) {
+                // Cancel any lingering so the linger timeout doesn't teardown this network
+                // even though we have a request for it.
+                bestNetwork.networkLingered.clear();
+                bestNetwork.networkMonitor.sendMessage(NetworkMonitor.CMD_NETWORK_CONNECTED);
+            }
             bestNetwork.addRequest(nri.request);
             mNetworkForRequestId.put(nri.request.requestId, bestNetwork);
             int legacyType = nri.request.legacyType;