For a more advanced and more up-to-date series of exercises in learning OpenGL - Joey de Vries has authored a comprehensive series of exercises and provided them online. See the following link to get started.

https://learnopengl.com/

The exercises designed by Mr. de Vries are coded in C++. I have recoded some of them in Kotlin and adapted them to the Android system. Here is a link to the Github repo where a selection of the exercises are completed.

https://github.com/jimandreas/AndroidKotlinLearnOpenGL

Imported content

The project does not use any supporting graphics libraries aside what is built into the Android Framework. The math support is provided by the Rajawali Math modules. The modules are converted to kotlin and are located in the java/org/rejawali3d subtree.

See also the Github repo:

https://github.com/Rajawali/Rajawali