Previous change meant we never had universal APKs but they are useful
This enables them again if you send a command-line toggle in, and then
uses the toggle to upload builds to github
This reduces built APK to 7.5MB vs 10.4MB
Careful consideration was taken to version range space so we won't exhaust it
Manual downloads (github attachments, mostly) are configured as armv7 since no
one uses x86 in real devices anymore - and armv8 devices can run armv7 code
