Make sure downloaded version of track plays in the queue if it is downloaded after the item has already been added to the queue

[mitchdowney]

There seems to be a bug where if a non-downloaded version of an episode is added to the queue, then the episode is downloaded later, the player will stream the episode from the queue instead of using the downloaded episode.

[mitchdowney]

We should also swap out the currently playing item if the user presses play before the episode finishes downloading.

[mitchdowney]

Attempting a fix for this in v4.12.13 c633521

#1314