This change makes adding ad events in live streams more robust by allowing ad
groups to grow in number of ads if more ad events are received than initially
announced by the SDK.
With the IMA prefetch feature, an AdPod can grow in size in certain conditions
like from initially 2 ads to 4 ads being part of the ad group. With this change,
if an additional ad event arrives while the ad group is still being played,
the ad group is expanded. If the event arrives late and the ad group is already
completed, a new group is created for the remaining ads.
This also covers the case where we join the live stream while an ad is being
played and we missed at least one LOADED event from the SDK. Ads of the group
before the first LOADED event are ignored in such a case.
PiperOrigin-RevId: 484214760
(cherry picked from commit 64e9e888)
