PNG crunching is not a deterministic process, especially the way aapt does
it. This makes the F-Droid builds not reproducible. The easy solution to
this is to pre-crunch the PNGs and commit them to git. It also makes the
final APK a tiny amount smaller, for whatever reason.
https://medium.com/@duhroach/smaller-pngs-and-android-s-aapt-tool-4ce38a24019d
This makes it a lot easier to setup all the testing stuff. Mostly,
I'm tired of fighting Android Studio's fragility, so I want to remove
as much non-standardness as possible in the hopes of improving that
situation.
closes#534https://gitlab.com/fdroid/fdroidclient/issues/534
