fix NPE in race condition.

Change-Id: Ic1df67f8a5379ff1cd804fb55e143f078e369ccf

Author: Tsu Chiang Chuang

core/tests/bandwidthtests/src/com/android/bandwidthtest/util/ConnectionUtil.java

@@ -44,6 +44,8 @@
 import com.android.bandwidthtest.NetworkState.StateTransitionDirection;
 import com.android.internal.util.AsyncChannel;
 
+import junit.framework.Assert;
+
 import java.io.IOException;
 import java.net.UnknownHostException;
 import java.util.List;
@@ -453,6 +455,11 @@ public boolean waitForNetworkState(int networkType, State expectedState, long ti
                 } catch (InterruptedException e) {
                     e.printStackTrace();
                 }
+                if (mNetworkInfo == null) {
+                    Log.v(LOG_TAG, "Do not have networkInfo! Force fetch of network info.");
+                    mNetworkInfo = mCM.getActiveNetworkInfo();
+                    Assert.assertNotNull(mNetworkInfo);
+                }
                 if ((mNetworkInfo.getType() != networkType) ||
                         (mNetworkInfo.getState() != expectedState)) {
                     Log.v(LOG_TAG, "network state for " + mNetworkInfo.getType() +