Add DisplayModeDirector support for UDFPS

UDFPS needs to lock to a given refresh rate in order to function
properly, so we register a listener for when it's enabled in order to
make sure it gets the right refresh rates.

Bug: 181682258
Test: atest DisplayModeDirectorTest
Change-Id: I54afb12f8e4f03a3b0c384112fc2d9b1806de719