[Settings] Code refactor

1. Replace the detection of screen on
2. Refactor updateCell method

Bug: 147263514
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=NetworkSelectSettingsTest
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=NetworkOperatorPreferenceTest
Change-Id: I1ae3ee4d1b62b488aeb2163f42878697b770be65
2 files changed