The Timeline, Tracks and MediaMetadata are currently provided
with a list of MediaItemData objects, that are a declarative
version of these classes. This works well for cases where
SimpleBasePlayer is used for external systems or custom players
that don't have a Timeline object available already. However,
this makes it really hard to provide the data if the app already
has a Timeline, currently requiring to convert it back and forth
to a list of MediaItemData.
This change adds an override for `State.Builder.setPlaylist`
that allows to set these 3 objects directly without going
through MediaItemData. The conversion only happens when needed
(e.g. when modifying the playlist).
PiperOrigin-RevId: 649667983
b2585aad0f