Use true present fence times in PowerHintSession duration calc

The current implementation of power hint session timing relies on
estimated present times rather than actual present fence times,
causing mis-timings when a vsync is skipped. This patch fixes that by
providing the known present fence times to the PowerAdvisor.

Present fence times are also renamed as such to keep naming consistent.

Bug: b/236423436
Bug: b/195990840
Test: manual testing
Change-Id: I3cb25269c6231470bd23cc8b145a21559aaa1c70