This CL before, onChanged(null) will cause PreferenceGroup
didn't update UI in ConnectedDeviceDashboardFragment.
This CL remove onChanged(null) and set unvisible of SliceView
in the constructor.
Bug: 142220754
Test: make -j42 RunSettingsRoboTests
Change-Id: Ib20db373430589c5c5efbe8a4c866b7fae4f3399
Reuse the PreferenceController and LayoutPreference however create
specific one for slice:
1. SlicePreference: container to inject slice view
2. SlicePreferenceController: handle updates for slice
Also add styles for it with default layout.
Bug: 120803703
Test: RunSettingsRoboTests
Change-Id: I6ab083ad57117e6198dcba37702a25213da78719