WallpaperCropper: Fix crash when set .gif as wallpaper

It returns an equivalent scaled cropBounds as true
crop bounds, then it set the rounded rect by rounding
"out" the true crop rect, this make the rounded crop
rect may out range of the original bitmap, then an error
will happen.

We change to check the rounded crop rect, if it is out
the range of original bitmap, we set the original bitmap
bounds as rounded crop bounds.

CRs-Fixed: 622582

Change-Id: I215ef2a0165adaaadb05c62dee741a8ea6926144