Add an alternate detection technique for WiFi_Regulatory

In addition to testing for ping packet loss, also test for
reception of a DEAUTH frame at the AP.  Adherence in some
devices can only be detected by packet loss (they leave
the channel silently) so leave both detection methods in
parallel.

BUG=chrome-os-partner:20691
TEST=Run test on daisy, lumpy and a WP2 device

Change-Id: Id8610d5650c1dc0edf0c51933377bdb33f11c676
Reviewed-on: https://gerrit.chromium.org/gerrit/66015
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Commit-Queue: Paul Stewart <pstew@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
2 files changed