[Wi-Fi] Fix some test failures of com.android.settings.wifi.details2

WifiMeteredPreferenceController2 always has a non null mWifiEntry, remove redundant test case
testController_resilientToNullConfig

Bug: 146479774
Test: make RunSettingsRoboTests ROBOTEST_FILTER=com.android.settings.wifi.details2
Change-Id: I8194476ea0f337e63b29ff73e9071f6df65d13af
2 files changed