FB19407598 — Adding a ToolbarItemGroup with .bottomBar placement causes crash on watchOS 26 beta 5

(This is what's causing the crash on launch of CARROT on watchOS 26 beta 5, both production and TestFlight versions.)

/cc @lorihc

What background color are you supposed to use for a UITableView presented as a sheet? If I use systemGroupedBackgroundColor, I don't get a glass background effect. Clear gets me the glass background, but when I present a detail view controller it shows the original view controller underneath until the animation finishes.