Fixed a crash when an image with an odd width/height was selected

Due to an internal rounding in the renderer, the calculations
for the cropping area could be slightly offset, getting out
of the image boundaries. I sanitized the rect by ensuring they
are inside the image.

Bug: 12174629
Change-Id: I5e08c83fe3e9cd48254fa6c8ba9cef77ab8a51a6