Correctly select peak refresh rate.

Currently we will get an arbitrary value that is greater than the
default depending on the order returned by the Display.

Bug: 180723012
Test: make RunSettingsRoboTests
      ROBOTEST_FILTER="com.android.settings.display.PeakRefreshRatePreferenceControllerTest"
Change-Id: Id2c99f2bea9c6b2814d82a9db3a417e4a93ee06d
3 files changed