wireless/monitor_wireless_connection_udp is a false alarm on Xenial latest kernel stack

[Taihsiang Ho]

This issue has been a while since some kernel version of Xenial 4.4. It reports message like [1] but actually the wireless still works.

[Steps to Reproduce]
Run sru.pxu testplan and found alarms like [1]

[Expected Result]
wireless failed to work

[Actual Result]
wireless still works

[More Info]
A submission example
https://certification.canonical.com/hardware/201606-22344/submission/122734/test/899/result/9159766/

Dell Vostro 5568 (CID 201606-22344) Xenial 4.4.0-96-generic

[1]
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/43)
Connection ubuntu-cert-bg-wpa registered
Connection ubuntu-cert-bg-wpa activated.
Device 'wlp2s0' successfully disconnected.
Error: Device 'enp3s0' (/org/freedesktop/NetworkManager/Devices/1) disconnecting failed: This device is not active
Error: not all devices disconnected.
Error: Device 'lo' (/org/freedesktop/NetworkManager/Devices/2) disconnecting failed: This device is not active
Error: not all devices disconnected.
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/44)
Connected to c8:d3:a3:68:91:b7 (on wlp2s0)
 SSID: ubuntu-cert-bg-wpa
 freq: 2422
 RX: 4427 bytes (35 packets)
 TX: 1178 bytes (9 packets)
 signal: -39 dBm
 tx bitrate: 1.0 MBit/s

 bss flags: short-slot-time
 dtim period: 1
 beacon int: 100
error: Name or service not known
Connection 'ubuntu-cert-bg-wpa' (0d584a37-fa18-4f45-bf40-101ab9aab654) successfully deleted.