Manifest caching

MediaTailor periodically and opportunistically caches source playlists to improve channel assembly performance and reliability. Sometimes, the cached version becomes stale compared to the origin version at your source location. To force MediaTailor to refresh the cached version of the source, call UpdateVodSource. For example, use this call when the embedded paths change in your source. Make sure that you always keep an up-to-date version of the source available on your source location, even if you see few requests from MediaTailor.