Summary:Images cropped using the ImageEditor were always given an alpha channel, even if opaque.
This causes them to be saved as PNGs instead of JPEGs (increasing memory and bridge traffic) and also causes unnecessary blending when they are drawn.
Reviewed By: fkgozali
Differential Revision: D2982682
fb-gh-sync-id: b65f361efd78e35f259836111b38d914bae49847
shipit-source-id: b65f361efd78e35f259836111b38d914bae49847