Add AR Core

[rusty-snake]

I (want to) use an app (StreetMeasure) that requires AR Core but works fine w/o GMS/Play-Services.
It would be good if Apps mirrors AR Core the same way Play services are mirrored.

I'm aware that the GOS team is not interested in maintaining a mirror of all the Google apps like Pixel Camera. However AR Core is not a "normal" app with an UI and a launcher icon, it more like a "system dependency" like Play Services or Pixel Camera Service which are both provided by GOS infrastructure.