The periodic updates are only meant to happen while we are in the
same period or ad. This was already guaranteed except for two cases:
1. The Player in a session has updated its state without yet calling
its listeners
2. The session scheduled a PlayerInfo update that hasn't been sent yet
... and in both cases, the following happened:
- The change updated the mediaItemIndex to an index that didn't exist
in a previous Timeline known to the Controller
- One of the period position updates happened to be sent at exactly
this time
This problem can be avoided by only scheduling the update if we are
still in the same period/ad and haven't scheduled a normal PlayerInfo
update already.
Since new MediaControllers may still connect to old sessons with this
bug, we need an equivalent change on the controller side to ignore such
buggy updates.
PiperOrigin-RevId: 532089328