SF: Offsets should be dependend on the refresh rate.

When switching to 90Hz, the time between vsync pulses is only 11ms, so it
doesn't make sense to have 6msec offsets. Adding the flags will allow us
to experiment with different offsets in the later stages through device.mk
file for two different refresh rates. Eventually, the refresh rates should
be coupled with the configs that indicate the refresh rate.

Bug: 122905996
Test: Added Fake class to inject into tests to keep consistant results.
Change-Id: Iffe7eb9dae6cd655c83e5b576306e3883ef1a56d