Improve Android app compatibility with Chromebooks

[kelchm]

I recently picked up a Samsung Chromebook Pro and have been using Spotify from the Play Store with it. While it generally works just fine, I have noticed a couple oddities that would be nice to have addressed.

1. Unlike YouTube or Google Play Music, 'closing' the Spotify app immediatly stops playback rather than continuing to play in the backgound (with playback controls accessible in the notifications). Even when I control playback on the chromebook from another device and a song is playing, no notifications shows unless the app opened.

2. The window cannot be resized