Thanks c-w-s for confirming that it's only iOS at the moment. I guessed as much when you didn't post again after our exchange above on 11 October, but the confirmation will help other Android users not to waste time looking for the new feature.
Fairly new and still being rolled out. The discussion above is brief enough to be worth skimming if you're interested in what to expect when (if?) it hits Android.
No sorry, I meant the US wanting a scan of your passport in general. I don't remember having to do this last time I went.