While a Skip Intro / Skip Credits prompt is up and the chrome is down,
Back walked the screen's staged chain and exited playback. On a remote
nothing else means "no thanks": left/right seek, OK takes the skip,
up/down raises the OSD. Declining an intro cost you the episode.
Adds a stage for it alongside the sheet and content-strip stages that
already run locally in the player controls. Gated on the same condition
as Select's skip path, off on phones (#1938), off without canControl,
and off while a screen-level prompt owns the key.
The claim is latched for the whole press: handleBackKeyAction acts on
the key-up, and the button's own 7s auto-dismiss can fire in between.
Co-authored-by: cajunflavoredbob <cajunflavoredbob@users.noreply.github.com>
