No. Stock camera has not been ported to custom ROMs(any aosp/cm based ROMs).
I swear this is the most asked questions. Please use google and or the XDA search tool to get this info rather than repeating the same questions that have already been answered, and again, and again
I'm not sure why anyone is still interested in flashing cm12.1 on a G4?
Development has ceased and I'm kinda sure things have deprecated.
Cm13 however is running strong, there is also an Omni build almost done(is aosp source, not cm)
The cm13 build and other ROMs based on cm have had a modified version of Snap Camera included. It is a rather good camera with manual controls. But it will never equal stock based camera app. On any device, this holds true. The stock camera apps rely on the stock framework files. And it is incredibly difficult to port a camera app to custom roms, never mind not lose quality