Revert "Bug 1027112 - [Homescreen] New wallpaper to replace current grass wallpaper r=vingtetun"

This reverts commit 42c35fd8cbf6b2489d0d76c81abfd2d3c6a2d46b.
Bug 1027112 - [Homescreen] New wallpaper to replace current grass wallpaper r=vingtetun
Bug 1030704 - [Collection app] Divider under pinned apps hidden r=ranbena