SurfaceFlinger: expose duration as part of phase offsets

expose app/sf duration together with the offset configs. These
will be used in the next CLs to calculate when to wake up the
corresponding EventThread.

Test: examine offsets and duration via dumpsys SurfaceFlinger
Bug: 162888874
Change-Id: Ifc1848358823570a34760f29ea975c286fbd8837
13 files changed