Don't show Wi-Fi icon if the level is -1

Bug: 195893448
Test: manual test
make RunSettingsRoboTests
ROBOTEST_FILTER=NetworkRequestDialogFragmentTest

Change-Id: Ifddc9aace42d1f024b7c861b1207f651061d790b
(cherry picked from commit 7e14668094ddb26f726f5282456b10afd11b75c5)
Merged-In: Ifddc9aace42d1f024b7c861b1207f651061d790b
1 file changed