Emulator: remove hardcoded isEmulator() logic in ImageWallpaper

Emulator can use host GPU for rendering and supports GLES 2 already.
The isEmulator() logic is not only unnecessary but also causes the
launcher to have black background.

BUG: 33788018
Change-Id: Ib6d942490e8808e202c444f96becec1b75953838
1 file changed