delete
Deletes a given localMediaItem from the local storage. This is a permanent delete that cannot be undone.
You should always favor batchDelete when deleting multiple items, as item deletion may lead into a system prompt if the picture was not originally added to the MediaClient by your application.
Scheduler: The returned Completable will operate on the IO Scheduler.
Return
a Completable which completes once the media item has been deleted (or errors if the action failed)
Parameters
localMediaItem
The MediaItem.Local to delete.