Create RestrictedTopLevelPreference for silky home

Based on UX design, create a new restricted preference for the items on
the top level page which don't need a the restricted icon and shouldn't
be grayed-out.

Bug: 168166015
Bug: 174964139
Test: robotest
Change-Id: If52b7d14c13d33f964a6b12612747db9323979a2