healthd: fix the over estimated battery capacity

Overwrite the gauge capacity with the backup one if the gauge capacity
reset to nominal.

Test: fake /sys/class/power_supply/bms/charge_full to nominal and
      check if it can be restored from /persist/battery/qcom_charge_full
Bug: 158838006
Signed-off-by: Jack Wu <wjack@google.com>
Change-Id: I4b85dd5e0c3ca929044aa8776294b841db7214e1
2 files changed