Mainly going by the camera specs: 12.3MP, f/2.0. And it "makes sense" for a phone maker to use the same sensor for two years in a row. At least I know Apple does that (sometimes even keeps it for 3 years, like it did with its first 8MP camera).

I think it would be weirder and less likely if they ordered a "next-gen" camera that had exactly 12.3MP resolution and f/2.0 lens, just as last year's camera. There's still a small chance I could be wrong, though, so just take it with a grain of salt. Perhaps Google will confirm it either way soon.