made examples compile and run on android

[jluuM2]

I had not seen the xbuild announcement, I am going to try xbuild. I made the example compile, it may be useful for others

[MarijnS95]

This looks incomplete (and untested??), these examples are "tailored" for simplicity with cargo-apk. Rather, xbuild should attain support for compiling crate examples out of the box and then none of this (besides maybe reducing the API level via manifest.yaml) will be needed.

Closing as "not the right way to approach this".

[joseluu]

Tested on my android phone