Implement getBatteryHealthData in HealthServiceWrapper

Extend the HealthServiceWrapper with the new getBatteryHealthData API,
introduced in the AIDL Health HAL v3.

Flag: EXEMPT statsd atoms/metrics changes
Bug: 343691107
Test: statsd_testdrive 10220
Change-Id: I2f4a7c420f97314089c202297f3a2e07c0272bf7
Signed-off-by: Alessio Balsini <balsini@google.com>