Wifi usability:  Add IP reachability lost into Wifi unusable event

IP reachability is a strong indicator of Wi-Fi network quality. Extend
the WifiIsUnusableEvent list to include IP reachability lost.

Bug: 129282057
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh

Change-Id: Ia759fc506a615e656aa6fa8493e4323d1e754646
Signed-off-by: Mingguang Xu <mingguangxu@google.com>
4 files changed