Adding comments to BatteryServiceDumpProto.

    optional bool are_updates_stopped = 1;

    // Plugged status of power sources

    optional android.os.BatteryManagerProto.PlugType plugged = 2;

    // Max current in microamperes

    // Max current in microamperes. This may be 0 if the device's kernel drivers

    // don't support it.

    optional int32 max_charging_current = 3;

    // Max voltage

    // Max voltage. This may be 0 if the device's kernel drivers don't support

    // it.

    optional int32 max_charging_voltage = 4;

    // Battery capacity in microampere-hours

    optional int32 charge_counter = 5;