This class is currently used by both search and slice, in the future
will be used by DashboardFragment to build controller list. So the scope
of this class is beyond search now.
Test: rerun robotests
Change-Id: If43ebca065aac31ad24f95a94bfe5be784109605
Autobrightness preference controller was accidentally removed from
display_settings.xml. Given that no tests were broken and this would
be a disaster for phone buddy & inline actions, I have added another
test which keeps a list of valid controllers that should exist in xml.
When more inline controllers types are added, they will be included
in this test.
Fixes: 72564979
Test: robotests
Change-Id: I40fe18f9118af9cec1c201632742d2949ff64be5
