Code review comment for lp:~paride/auto-upgrade-testing-specifications/set-debian-frontend

@Brian I amended the commit message. I'm not mentioning the upgrade process anymore as that part of the commit message was imprecise: the Debian frontend is handled by auto-upgrade-testing via

 do-release-upgrade -f <frontend>

and apparently auto-upgrade-testing sets it to noninteractive (DistUpgradeViewNonInteractive). We can evaluate changing this in the future to spot blocking debconf questions, but for the moment this is how it is.