power/stats: Add duration field to EnergyMeasurement am: 68511c759f am: 4c4c798ea4

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1576528

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I4716c650f764a533b0b8b5ff982ebbbce5fc04af