`fdroid publish` now includes OTA ZIPs and related source
This adds support for publishing ZIP files which were built with fdroid build. This is for "Over-The-Air" (OTA) update ZIP files for flashing to ROMs. The first example of this is the Privileged Extension, which must be installed by flashing an OTA ZIP on Android > 5.0. This should be the final step to finally publishing the Privileged Extension as an OTA ZIP that people can flash to their ROMs instead of gapps.