Google is ditching the screen on its latest wearable and betting hard on its AI health coach. The new Fitbit Air is a slim, screenless band with a removable sensor with the sole job of collecting health data in the background, removing the distractions of notifications, apps and stats.  Read more: Fitbit Air, Redesigned App and an AI Coach: Google Is Overhauling Its Health Ecosystem This back-to-basics move echoes the earliest Fitbit devices , but with a very different end game. Where those first bands only counted steps, the Fitbit Air feeds a much broader stream of biometric data into Google's evolving health ecosystem that seems to be increasingly centered on AI. At $99, the band is just the ticket to get you in the door. The main event is Google's recently launched Health Coach, part of the Google Health Premium (formerly Fitbit Premium ) service. The premium service will run $10 a month or $100 a year when you purchase an annual subscription.…