Keep "Resetting your internet" when screen rotates

- The fragment of Internet Settings will be destroyed and recreated when screen rotates

- Move connectivity recovery class into singleton class to avoid service being killed when fragment context is destroyed

- Check if connectivity is recovering when fragment is recreated and show resettings message if necessary

Bug: 202802736
Test: manual test
atest -c InternetResetHelperTest
make RunSettingsRoboTests ROBOTEST_FILTER=NetworkProviderSettingsTest

Change-Id: Iae9585ff8366b8b71b4c39dc0ec7e87a0320fa5a