[Wi-Fi] Fix test fails in WifiDetailPreferenceController2Test

Sign in feature is integrated in WifiTraclerLib, change the test cases
to verify if WifiEntry sign in methods is called.

Bug: 151696220
Test: make RunSettingsRoboTests ROBOTEST_FILTER=WifiDetailPreferenceController2Test
Change-Id: Ia0157f5a96c700e5596c00cef873c8f5016d6442
1 file changed