BatteryMonitor: report current_now in uA

/sys/class/power_supply/*/current_now should return uA and the HAL
expects uA too.

Test: VtsHalHealthV2_0TargetTest
Bug: 136717180
Change-Id: I675be1ae645413b9494af4a5d49955aad5bd4f2e
(cherry picked from commit e5bd5f914f1bfdf94379ea0c2d72d58c06cfd25e)
Merged-In: I675be1ae645413b9494af4a5d49955aad5bd4f2e
1 file changed