Update the default wellbeing package config.

defaultWellbeingPackage is now deprecated and should not be used.
Instead, point all references to the new systemWellbeing config.

Bug: 233363529
Test: atest AmbientDisplayAlwaysOnPreferenceControllerTest
Test: atest DarkModeCustomBedtimePreferenceControllerTest
Test: atest DarkModeScheduleSelectorControllerTest
Test: atest WhenToDreamPreferenceControllerTest
Test: atest AfwRequiredAppsTest
Test: atest ManagedProvisioningRequiredAppsTest
Test: atest WellbeingTest
Change-Id: Idaa1690b509e639bde982a0589e40238b62b4f3d