SF: Cleanup FrameRateOverride into a single boolean

The enums representing the various configs for overriding a layer's frame rate are no longer needed as the logic has been simplified.

This simplification allows to make a lot of the code easier to read and to remove extra functions.

Bug: 356986687
Test: presubmit
Flag: EXEMPT refactor
Change-Id: I122c550644c8049de188cb321a317c59b1d94961