Update wallpapers

Change-Id: I7b35d523dd64c8503d8cde32c645960538d3c238
Revert "Update wallpapers"

This reverts commit 2baac8d45492d32f909c6dcd29e133bda30f792a.
Restore 720dp wallpapers

Change-Id: Ibafa9195ac3ac2e4666a35a6fe8f059d5798ee87
Simplified default workspace

Change-Id: I2fc577cc1a74e35ad115d65079a43632df248070