TBA: Only ship one tor binary per apk

Orbot bundles all the binaries into a single apk and ships that, this means they only produce one apk for all the platforms they support. Unfortunately, with fennec, we must create one apk per arch. However, we didn't modify orbot's build system so it only includes one binary for the target architecture, therefore our apks include tor binaries for armeabi, armeabi-v7a, and x86.

This causes a little bloat and we can avoid this, but the more problematic result is it confuses Google Play such that Google Play thinks each apk supports all of those architectures, therefore we can't upload one apk for armv7-only and x86-only, because one of them will override the other.