A device set by UTC offset rather than by city reports an id like
Etc/GMT-9, which is UTC+9; the local row took its last segment as the
city and read "GMT-9". It is now named by its actual offset. LocalClock
takes the already-resolved home zone rather than resolving it a second
time, the tab reads both of its settings from one subscription, and the
local row falls back to the unknown-zone sentence for TalkBack instead
of an empty time.