Currently, users don't know if the wifi description shows
"No internet" means it really doesn't have internet access or no
internet is because of private DNS resolution failed. So, Add a
new description for wifi when private DNS is broken.
Bug: 113242081
Test: make -j44 RunSettingsRoboTests \
ROBOTEST_FILTER=WifiDetailPreferenceControllerTest
Change-Id: I44a7e51cf76dc3f2a6b9583f226af6649f9b1f5f