Merge "Add stats session end timestamp and duration to BatteryUsageStats" into sc-dev am: 14bc81b9 am: 7174c3ad

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14455100

Change-Id: I8e8817916bafce3aa0031e2015f4342736d40696