Unable to update Google App on Nexus 6P running Android N Developer Preview
This is normal behaviour. My Nexus 6P also runs the developer preview and has this version: 5.14.15.NYC.21.arm64.

The reason it won't update is because the actual version code is higher then the one on Google Play. That's because it is targeted to Android N.

I wouldn't recommend you to install the version on Google Play, because it probably will keep crashing because of no Android N support.





In the following screenshot you can see the app has a very high Version Code and the Target SDK is set to 10000. (=Developer preview)



(Click image for larger version)