CHERRY-PICK: Add wireless antenna scan test case by using tcpdump to monitor beacon

This test case needs association with AP.
Please DO NOT add exclusive=['NETWORK'] option in the test_list.

spec_dict format is:
{((SSID_AP1, FREQ_AP1, PASS_AP1),(SSID_AP2, FREQ_AP2, PASS_AP2)):
 {"main": strength_1, "aux": strength_2, "all": strength_all}}
Password can be '' or None

test_list example:
      OperatorTest(
          id='WirelessAntenna',
          label_zh=u'天線',
          pytest_name='wireless_radiotap',
          dargs={'device_name': 'wlan0',
                 'spec_dict': {
                     (('antenna_test_5G_1', 5745, '1234567890'),):
                         {"main": -60, "aux": -60, "all": -60},
                     (('antenna_test_1', 2412, ''),):
                         {"main": -50, "aux": -50, "all": -50}},
                 'scan_count': 10,
                 'switch_antenna_sleep_secs': 1})

BUG=chrome-os-partner:25753
TEST=manually test on DUT with Intel WP2 7260 chip

Change-Id: I81458388dbedcfe5d301cae3372941259a236264
Reviewed-on: https://chromium-review.googlesource.com/187985
Reviewed-by: Paul Stewart <pstew@chromium.org>
Reviewed-by: Bowgo Tsai <bowgotsai@chromium.org>
Tested-by: Heng-ruey Hsu <henryhsu@chromium.org>
Commit-Queue: Heng-ruey Hsu <henryhsu@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/189364
Reviewed-by: Heng-ruey Hsu <henryhsu@chromium.org>
Commit-Queue: Jay Kim <yongjaek@chromium.org>
Tested-by: Jay Kim <yongjaek@chromium.org>
2 files changed