External Display render rate at mode rate

Some external displays physical refresh rate
modes are slightly above 60hz.
SurfaceFlinger will not enable these display
modes unless it is configured to allow
render rate at least at this frame rate.

Change-Id: I4b16a874501a08cf5bda15d7ac3d0a75571bcf6f
Bug: 314733202
Bug: 242093547
Test: atest DisplayModeDirectorTest