Magic Cube

1) Relax requirements as to OpenGL ES ( now only 3.0 required )
2) fix a crash in Solving state

(Hopefully) make the Dialogs NOT disappear on clicks outside (previously this wasn't working on Android 9).
Lower API requirements to 21.

Minor tweaks to the 'Prev' buton in Solving state;
Relax requirements in the Manifest - now only 'android.hardware.faketouch' supporting device is required, i.e. something that supports basic point-click-drag-unclick. No need for full 'android.hardware.touchscreen' thing with its multitouch silliness.

Add a 'withdraw move' button to the Solving UI state.

Bugfix

Make chances to randimoze a given row when scrambling dependant on the type of Object.

The point: in case of the Cube, all rows should have equal chances. In case of the Pyraminx, the smaller the row, the smaller the chance should be. In particular the trivial 4 corners of the tetraherdon should have a very small chance to be selected.

Bugfix.

Each object size now has its own number of levels (not always 18!)

Reorganize UI of the Play state.

The 3x3x3 Solver finished - here the last piece of work, locking the centers of the 3x3x3 cube in place so that RubikStateSolver's color picker cannot change them ( the CUBE3 solver assumes this )