[SB][Wifi] Remove passpoint-related values from wifi pipeline.

[WifiEntry.title] correctly fetches the SSID for both typical wifi
networks and for passpoint/OSU APs. Now that we're fully moved over to
WifiTrackerLib, we can remove all the passpoint/OSU-specific logic.

Bug: 292534484
Flag: EXEMPT refactor
Test: atest WifiRepositoryImplTest WifiInteractorImplTest
Test: smoke test of Internet tile when wifi is connected
Change-Id: I0ca61f351e1e7a1dc39174a2e221832a4ea69497