power/stats: Add duration field to EnergyMeasurement

Bug: 168831752
Test: dumpsys android.hardware.power.stats.IPowerStats/default
Change-Id: Ie588854d8bbe24c1c3492d547ede4aa249b1d50f
Merged-In: Ie588854d8bbe24c1c3492d547ede4aa249b1d50f
3 files changed