Fix the bug of showing the "Smooth display" item in the search result.

The controller can't be created when Settings Search gets the
non-indexable keys. So Settings Search can't get the correct value
from it.
The controller creates the Handler without the parameter in constructor
and causes the exception. It should use the main Looper of Context as
the parameter to create the Handler.

Fixes: 160179400
Test: run robotest and observe the search result
Change-Id: I6f9bf6de087ae776e8d531ff59d28966aee96b7b