Merge "Fix a crash when exiting the DevTools Connectivity page." into nyc-dev

Author: Chris Iremonger

apps/Development/src/com/android/development/Connectivity.java

@@ -486,7 +486,9 @@ public void onDestroy() {
         mCm.unregisterNetworkCallback(mCallback);
         mCallback = null;
         unregisterReceiver(mReceiver);
-        mWml.release();
+        if (mWml.isHeld()) {
+            mWml.release();
+        }
     }
 
     @Override