I installed the following file for the Google Camera HDR+ and it worked. I'm using the H-ROM G6 Port, idk if that is a must.
Doesn't matter what you choose, even opening settings and closing them without touching anything makes the app crash. The hdr+ switch is just a dummy, the photo quality and everything is just the same as stock google camera.
Added Super Res toggle.
Added DCI-P3 color space toggle.
Added Portrait zoom selection.
Revert stock icon.
Thanks to cstark27 (loveu3000).
Note: I am well aware that 1/4 (120FPS) isn't working there is bug in the system even stock cam port can't use it. If you want to get rid of the credits message select a lib from the lib loader and force close the app.