Fix for updating TCP buffer size when switching network type

When PDP connects in GSM network, the TCP buffer window size is
set to max 8760. If the phone swicthes to UMTS, the TCP buffer
size is not updated to UMTS, i.e. GPRS buffer size is still
used with limited data transfer spead as a result.
This fix makes sure the TCP buffer size is updated when
switching network type.

Change-Id: Iaa527c84f56cae108f4c7276bbed10552faaff6c

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

@@ -2490,6 +2490,11 @@ private NetworkStateTracker makeWimaxStateTracker() {
                     //       @see bug/4455071
                     handleConnectivityChange(info.getType(), false);
                     break;
+                case NetworkStateTracker.EVENT_NETWORK_SUBTYPE_CHANGED:
+                    info = (NetworkInfo) msg.obj;
+                    type = info.getType();
+                    updateNetworkSettings(mNetTrackers[type]);
+                    break;
                 case EVENT_CLEAR_NET_TRANSITION_WAKELOCK:
                     String causedBy = null;
                     synchronized (ConnectivityService.this) {