This is just my presumption, but I don't think there will be a noticeable difference from S5 to S7, in the camera department. There may be some difference if you take a very hard look and comparison but otherwise not ground breaking. This is from what I observe when comparing my lower end android phone with P9 and iphone 6. Even if the newer model comes with manual control and raw, the acceptable iso level is so low that changing shutter speed, iso and aperture makes little difference.

Again, just my opinion as I don't own either S5 or S7. You better just do some research on your own via studio comparion in dpreview and demo set. Otherwise, I would say if you want to upgrade phone, better look at the overall package before looking into camera.