buffet: StartDevice automatically after a short delay

BUG=brillo:15
TEST=buffet_Registration confirms that we StartDevice
automatically shortly after registering.

Change-Id: I6c903e67f0556c7db817e126c72711f7d781592d
Reviewed-on: https://chromium-review.googlesource.com/249441
Tested-by: Christopher Wiley <wiley@chromium.org>
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Christopher Wiley <wiley@chromium.org>
3 files changed
tree: c98ecefb39be1230eda549520193eaf122605a4e
  1. buffet/