Update logging util to not crash on null

The logging for the wifi access points could cause a crash if
a bad scan result is passed in for any reason. This CL updates
it to be resilient to that by doing a best effort logging of
the scan results.

Bug: 74507895
Test: robotests
Change-Id: I4eaf948d7279374b1f4d009ef6f4fd0119f22ab7