Gallery: Preview Should show present wallpaper by default

[abhay-raizada]

Use Wallpaper.get()

[abhay-raizada]

Maybe even after wallpaper changes.

[nemani]

No point in showing the current wallpaper in preview. after a change...

[abhay-raizada]

@nemaniarjun makes the whole thung more dynamic/pleasing

[nemani]

Oh! I though you meant when we change using set wallpaper. when changing using scheduler, this is a cool idea