Only go to the afe if _is_conductive is needed.

Many tests do not care if the rig is conductive.  This moves the
cautotest lookup to be only done if needed.

TEST=network_WiFi_RateControl with:
  --args=conductive_rig=True/1 : run test don't hit afe
  --args=conductive_rig=False/0 : abort test don't hit afe
  --args="" : hit afe, run based on labels
BUG=None

Change-Id: Ife01d790cb6d531087a4e952fa195cf439895462
Reviewed-on: https://chromium-review.googlesource.com/275058
Reviewed-by: Kris Rambish <krisr@chromium.org>
Commit-Queue: Kris Rambish <krisr@chromium.org>
Trybot-Ready: Kris Rambish <krisr@chromium.org>
Tested-by: Kris Rambish <krisr@chromium.org>
2 files changed