Since this guide was made before they introduced Themes, there is no need with this anymore.
See how your app would look like with Holo or Material Theme in MIT AI2 Companion..
The sad thing is when you build your app, you get the old theme, you will then have to go through the procedure in the link below as well as some additional files to make it look as when you tested with Companion.
And then there’s a couple of things I can not control directly with theme yet.
Note: this is just for testing and to see if it’s possible, so if you want to try you do so at your own risk..
Based on Light Theme, API Dependent, Old Theme -10, Holo +11, Material +21.