[Android][Playlists] Do not automatically clear caches!

[Devrin]

A constant problem I appear to be having is when my login to Spotify times out and I have to log back in all of my downloaded playlists are gone. This have eaten my data several times as I like listening to my playlists at work where I am on Cellular. I am pretty good about downloading my lists on wifi, but when I have that disconnect at work, I can download the playlist again, or just not use Spotify for the day... Frustrating!