Get WiFi SSID from WifiManager broadcast rather than function call.
By getting the WiFi SSID from the broadcast instead of a function call
the ACCESS_WIFI_STATE permission is not required. Not needing this
permission is important for Cronet embedders as this permission is now
in its own catagory and requires manual intervention during auto-update
as per the new permission policy:
https://support.google.com/googleplay/answer/
6014972
Review URL: https://codereview.chromium.org/
747553002
Cr-Commit-Position: refs/heads/master@{#305478}