Fix issue of failing to launch camera when tapping input tag.

The tag is <input type="file" accept="image/*;capture=camera">.
Chromium has already implemented a better file chooser for android,
so bypass that implemented by Cordova.

BUG=https://crosswalk-project.org/jira/browse/XWALK-2148
Merge pull request #130 from gaochun/2148

Fix issue of failing to launch camera when tapping input tag.