Most of the team? I only know that Rob Pike and Russ Cox are Google employers. And I have the impression that they are working mostly on Golang and some distributed infrastructures. Did they employ any other inferno developers?

About eleven people who once worked on Plan 9 and Inferno are now at Google: http://cm.bell-labs.com/cm/cs/alumni.html

Thompson, Pressotto, Weinberger, I think (?). Not sure they'd want to work on Infernoogle anyways after so long...

Most likely, because at the beginning the Android team got a few well known Sun/JVM expatriates on their architecture team, like Chet Haase and Romain Guy among others.

Does anyone from Plan 9/Inferno work on the Android team at all?

Well, Rob Pike created Go based on Limbo. This language becomes more and more popular. It is not in Android, but Google actively use it (probably in Google Play too).