android: Port ndk-build Makefile magic to gradle
Submitted by Sebastian Dröge (slomo)
Link to original bug (#773464)
Description
This should also get us rid of bugs like #773401, which are happening because shell/Makefile are a bit silly about newlines and whitespace... and behaving different everywhere. groovy is not great but at least does not have these problems.
Not sure which parts should be done in gradle though, and which in ndk-build. Source file generation at least should be gradle