[Merge] ~utkarsh/ubuntu-release-upgrader:prep-final-release-for-mantic into ubuntu-release-upgrader:ubuntu/main

[Utkarsh Gupta]

"The diff has been truncated for viewing." - aaaaaaaah, that's why my tests diff won't show up. Fair.
-- 
https://code.launchpad.net/~utkarsh/ubuntu-release-upgrader/+git/ubuntu-release-upgrader/+merge/452839
Your team Ubuntu Core Development Team is subscribed to branch ubuntu-release-upgrader:ubuntu/main.