autotest: Don't expect .cros in hostnames for RvR

Fix a problem where RvR tests explicitly depend on the user passing the
.cros domain as part of the hostname.  While here, import some missing
modules so that meaningful errors are fired.

BUG=None
TEST=RvR tests start successfully.

Change-Id: I9242d13bee11641344df1c7dd2359ab4beeba6a3
Reviewed-on: https://chromium-review.googlesource.com/167137
Tested-by: Christopher Wiley <wiley@chromium.org>
Reviewed-by: Wade Guthrie <wdg@chromium.org>
Commit-Queue: Christopher Wiley <wiley@chromium.org>
2 files changed