Nikkei did say NX would run on Android. Nikkei is almost always right even when Nintendo denies their reports.
IMO they are right (mostly) but it will be a custom version of Android with Nintendo's own storefront so they can control it.
I don't think it would be a phone though, it could just be like a tablet/mini-tablet. Runs NX games, VC games, Android apps (as selected by Nintendo).







