Before this change a timeline update of a live content
source has produced a timeline refresh before passing
the timeline to the ads loader. When in such a case
the ads loader updates the ad playback state, a
second timeline refresh is trigger that then
includes the updated ad data also. This can result
in a timeline being pulished with stale ad information.
This change prevents this by introducing a boolean
return value that requires the ads loader to signal
whether the ad playback state has been passed back
to the source. This ensures that an update of
timeline and ad playback state produces a single
timeline update and is published in sync.
PiperOrigin-RevId: 748288650
fd8547fc3a