Call MediaControllerCompat.Callback#onSessionEvent from MediaLibraryService

[Yangwoqizuo]

A function calling onSessionEvent is needed(maybe broadcastCustomCommand?)
PS:
MediaControllerImplLegacy#onSessionEvent will call onCustomCommand(means MediaBrowserService can call Media3's onCustomCommand)
, so is there any way to let MediaLibraryService call MediaControllerCompat.Callback#onSessionEvent?
(Media3's MediaLibraryService call legacy MediaController's onSessionEvent)

[tonihei]

Thanks for the request! This looks like an oversight that should be added to the library as you described. I'll mark it as a bug and we can fix it in the next release.