[Provider Model] Add Wi-Fi toggle slice

- Reuse “Turn on networks” slice

- Add "Turn on Wi-Fi" slice
  - Show Wi-Fi end icon

- Screenshot:
  https://screenshot.googleplex.com/63pdow7dJh3tTw7

Bug: 181858434
Test: manual test
atest -c TurnOnWifiSliceTest \
         InternetConnectivityPanelTest

Change-Id: I82de79fd45e99d2fe82554437bde50068dc1ae00