Fix 2582241: Update selection based on user setting instead.

When the user adds a DPM, Settings removes all display
timeout options with t > maxTimeout. It was incorrectly
setting the preference to maxTimeout.

The corrected code picks the user's preference if less
than maxTimeout or nothing otherwise.

Change-Id: I5a47fdce89f4cf216fd76bb585c3c0120b39db92