BatteryStats: Fix units on battery charge counter

The unit for the battery charge counter is in micro-Ampere-hours, not coulombs.
We store the value as uAh but display it in dumpsys as mAh.

Bug:27174034
Change-Id: Ib5cc1ee1c5c191336a3e1f18dbb12c38e833f8d0
4 files changed