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
700c113218