Android Legacy Version (Pre-SAF) for the Play Store

[Ghabry]

The Play Store requires SAF (Storage Access Framework) usage since November (see #2434).

SAF requires Android 5.0 or newer.
Maintaining SAF and non-SAF in the same codebase is lots of work, considering that we run out of devices that are Android 4.x.

Easiest solution is publishing a known working versions (0.7.0?) in the Play Store that target users with Android 4.x. That version will get no UI updates or usability updates anymore but sometimes the easyrpg_android.so file is recompiled and updated. (also that version must report that it is incompatible with Android 9 and newer because without SAF no files are readable)