WAIT_OUTSIDE_ADJACENT
Allow the SyncMediaPlayer to play continuously in the adjacent (previous and next) ranges of content.
The SyncMediaPlayer should wait for synchronization if its current timeline position is before the previous range of content, or after the next range of content.
This mode allows the SyncMediaPlayer to play continuously between pages, as it can keep playing content on the next page while the ReaderView is navigating to it.
If the pages do not contain any sync media, so that the playback position is after the next range of content, the SyncMediaPlayer will wait until the ReaderView and the SyncMediaPlayer are synchronized before resuming playback.