Currently, repeating the same item (via seekNext/Previous) implicitly
results in a seek to the default position of the current item, which
looks exactly the same as a direct seek. As a result, we don't send
onMediaItemTransition as we would for every other seekNext/Previous
call.
This can be fixed by explicitly marking the repeat case in the internal
BasePlayer/ExoPlayerImpl methods, so that the callback can be triggered.
Issue: google/ExoPlayer#10667
PiperOrigin-RevId: 481951788
(cherry picked from commit 76ce0cc6)
