SF: Dispatch frame rate overrides to pacesetter

...not the active display, though they are the same display in practice
(until pacesetter candidates include external displays).

Remove the Scheduler's round trip through SurfaceFlinger to look up the
active display.

Bug: 255635821
Flag: EXEMPT refactor
Test: adb shell service call SurfaceFlinger 1039 i32 <uid> f 30
Change-Id: I2eb6fe9214dcb6dbdb26676a1dc62207a2a84ba4