If you have same problem, follow these steps carefully:
1. Export your project to cordova, don't forget to select "Uses Camera" and "Uses Media" under permissions window
2. Open latest build Intel XDK, and import your project. Use cordova plugins: YES
3. Click PROJECTS button on the top left window in the intel XDK project window.
4. In the CORDOVA HYBRID MOBILE APP SETTINGS tab, select plugins:
5. In the Build settings you can use crosswalk version 12 or anything else, it's up to you
6. Now in the Build tab, Build your project in the Crosswalk for android.
If you following these steps carefully, then you'll not get any error when opening file chooser in the android device. You can open and select image from gallery, uses front or rear device camera, uses dropbox and anything else.