Improve Offline Mode

[jettycatarmy]

On Android devices, Offline Mode is too restrictive, but using the other data-saving options (data saver, disable Canvas, no Smart Shuffle, audio-only for podcasts, only download over wifi) I still can use 50mb in just a few hours while only listening to podcasts (with the screen off).

But Offline Mode is like bringing a gun to a knife fight.  It's so restrictive I can't even search within downloaded playlists for downloaded songs.

And constantly switching between Offline Mode and Online Mode is annoying.  It can't be safely done while driving, either.