Remove unused and repair broken Android/Dalvik code

The builds for compile targets Android and Dalvik are broken for a long time, and the code is mostly outdated.

In this issue, we want to

* remove unused code and build logic
* and repair broken code.
* provide hooks to the android monocle implementation so that external code can trigger events (rotation, touch events,...)

Since JavaFX is now leveraging Java syntax that is not available on the Android (Dalvik) platform, it makes no sense in maintaining the code that allows to run JavaFX on Dalvik. It does make sense though to run JavaFX code on an OpenJDK-compliant Java 11+ VM on Android (either via AOT or JIT)