This removes the AAR binary from the repo as it isn't needed anymore. Also room schema migrations will need to be one manually in the future as schema export doesn't seem to work in AOSP.
This instantiates all sorts of classes down to Restore which accessed the streamKey that is still unavailable at this point. Now it is only instantiated lazily when actually starting a restore.
Previously, we would put our files directly in the root of the storage location and delete any existing backups there. When used by different devices or user profiles, these would keep deleting each other's backups.
