Opencv for Android with externalUVC camera

I am trying to use an external USB webcam with my dragonboard410C running Android 5.1 This is what I have been able to do so far. 1. Build OpneCV 3.0 Android on my Windows machine 2. Build and deploy camera preview sample on the board. I had to change the sample target from Androd v 11 to 22. 3. But whenever I try to run the sample I get the error that "It seems that your device does not support camera(or it is locked)" I did some searching and there have been several solutions proposed online 1. The Android Manifest file does have this line "" 2. The sample app does have permission enabled for camera access By the way, I could get the camera working on this board with a third party app. So nothing wrong with the camera. Any tips and help appreciated.