Opened from Settings, the backup screen has no calendar manager underneath,
so popping back landed on Settings. The action now opens the manager, which
is still a plain pop back when the manager is what opened the screen.
The failure state was one long string set as a headline. It now has a tonal
icon, a short headline and a supporting line, capped at a readable measure —
and the screen hands it an unscrolled column so it can actually centre.