Adopt buildozer-action

[Julian-O]

At the moment, one lone hero, ArtemSBulgakov, is maintaining a Github action to build a package with Buildozer (for Android only?).

It is published in the GitHub Marketplace and maintained on GitHub under an MIT License.

The action is important to the Kivy project; it is mentioned in the Buildozer README. It is demonstrated by the Kivy Pong Demo repo.

But look at the low-quality of the Issues raised against it, and the low quality of the Pull Requests. The poor maintainer is dealing with people confused by Buildozer, sending him support requests that should be dealt with on our Discord.

I think it is important enough, that Kivy should be making sure it thrives and isn't dependent on a single maintainer. We should approach the maintainer and offer to host the repo under Kivy, if he is willing.