Handle the render frame rate from SF

SurfaceFlinger render rate might be a divisor of the display
physical refresh rate. Plumb this throught DisplayManager and return
that value when apps call Display#getRefreshRate

Test: atest FrameRateOverrideHostTest
Test: atest LocalDisplayAdapterTest
Test: atest DisplayManagerServiceTest
Bug: 259740021
Change-Id: I1a6925f112bc982371aafe31deb56f2430801fac