1. The offloadSchedulingEnabled value doesn't need to be in
PlaybackInfo because it's never updated in EPII.
2. The sleepingForOffload value in EPII wasn't updated explicitly
(just via the return value of a method). It was also only
meant to be enabled while the player is actively playing, but
confusingly triggered from a path where the player may
theoretically be buffering as well.
3. The offload sleeping (=not scheduling doSomeWork) was interwoven
into the actual scheduling code making it slightly hard to follow.
This can be improved slightly by keeping the offload sleeping
decision and the scheduling separate.
PiperOrigin-RevId: 457427293
Where this introduced an inconsistency (e.g. assigning to something
called `windowIndex`), I generally renamed the transitive closure of
identifiers to maintain consistency (meaning this change is quite
large). The exception is code that interacts with Timeline and Window
directly, where sometimes I kept the 'window' nomenclature.
#minor-release
PiperOrigin-RevId: 407040052
