I decided to look at that and come it with a solution. I an not a Dev so I couldn't. But while clicking pics one day, I found advance option in stock camera in moto g to have these features.
To go to advance option on stock camera of moto g, first open the camera app then hold your phone horizontally. Now open settings by dragging your finger from left to right, when settings would open you can see a bug on the bottom on the right side of the screen. Click on this bug, and voila you'd be in advance configuration of the camera app. From here, you'll be able to change the size of your pics, can add face detection in front cam, touch to focus and many others.