SF: Move present timing to FrameTargeter

Split out from I2c27dc709afd1f33bddbf9c2ca1cd61dd335f66c.

Store earliestPresentTime on the FrameTarget, like expectedPresentTime,
so it can be stored per display.

Add FrameTargeter::computeEarliestPresentTime. This calculation was
previously done in SurfaceFlinger, using data mostly contained in the
FrameTargeter. This will simplify computing this per display.

Move computation of the earliestPresentTime to
FrameTargeter::beginFrame. Add a scheduler::Feature to track whether
ExpectedPresentTime is supported.

Make previousFrameVsyncTime and wouldPresentEarly protected, now that
they are only called by FrameTargeter (subclass) and tests.

Make the test a friend of FrameTarget for accessing the above methods.

Bug: 255601557
Bug: 256196556
Bug: 259132483
Test: atest libscheduler_test:FrameTargeterTest
Test: atest
        libscheduler_test:FrameTargeterWithExpectedPresentSupportTest

Change-Id: Ib927935de6ba2b7b8d5037b42eb635ae92019634