Wifi: Add scanning, activity time and API

Addition of Wifi Scanning time to Aggregate BatteryStats

Addition of Wifi Active time to BatteryStats (aggregate)

Addition of API to obtain Wifi battery stats for power drain diagnostics.

BUG:67213886

Test: Manual
Change-Id: I4f4c27ba839017d44feca685a4fae2f130d31765
8 files changed