Introduce WifiRoamScansPreferenceController

 - Create new WifiRoamScansPreferenceController
 - Create controller inside the DashboardFragment
 - Port logic from DevelopmentSettings into the controller

Bug: 34203528
Test: make RunSettingsRoboTests -j40
Change-Id: I967944e8d22d985035c94874d13e02c3f5e70781
3 files changed