Fix wallpaper placement + performance improvement

Wallpaper would have the wrong placement during
first frame because it would be center aligned
in a surface that's not big enough.

Also removed old OpenGl implementation, in favor of new
hardware accelerated canvas.

Change-Id: Ic9c9eaa817e1f6494aa5431d8278f2c28b2c45a9
Fixes: 66926914
Test: set wallpapaer with different offsets, orientations and devices