Comment 8 for bug 1920836

Another thing to note/expect: ua client in release in xenial and bionic at the moment is a completed incompatible commandine (which we are planning on SRUing prior to Xenial ESM, so `ua status --format=json` will not work on something < version 20. I'm fairly certain you shouldn't care to support this old version of ua-tools, but you might want to just do a pre-flight check on Xenial and bionic 'ua version' >= 20 and return (False, False) in that case notiing that those environments should update their versionn of ubuntu-advantage-tools.