HelloGluon example (aka DummyApp)

This example is based on the Hello Gluon from Gluon Mobile samples. I called the first version "Dummy App" and only later realized that it would be better if I use the same project for more complicated examples.

The source code is just one file: https://github.com/makingthematrix/scalaonandroid/blob/main/src/main/scala/io/makingthematrix/scalaonandroid/dummyapp/Main.scala

Here's a screenshot