SF: Adding Scheduler information into dumpsys

Adding helper classes to keep track of how long we spend in given refresh rates.
We assume that DOZE mode is refresh rate 30 Hz. The other rates we get from the
list of configs stored on the device.

Currently assuming there are up to three modes:
enum class RefreshRateType { POWER_SAVING, DEFAULT, PERFORMANCE };

Test: Tests for the classes coming in next CL.
Bug: 113612090
Change-Id: I6c8226ebdb4bcdffab457121d408500973c7f89e