It's not just the camera app itself - if you look at the Google source code for the Android camera app, there's a check for whether or not the camera supports exposure control, as per this entry in the Android developer reference,
Camera.Parameters | Android Developers , and presumably if that fails the camera does not show any exposure control. I've seen screen shots from other phones of the camera app showing exposure control. Same is true for other camera apps - they either don't show exposure controls, or if they do, they have no effect.
Downloaded the Optimus U (apparently supports exposure control) source code from LG,
Open Source Main , with the intention of digging into the camera kernel driver, comparing it to the Optimus S code, porting it over, and recompiling the entire S system. Is there a precedent for this? Will it work if I do the driver correctly? Anyone have experience writing drivers? Is there any closed-source material excluded from LG's download or Google's Android repository?