Export methods from BatteryEntry and controller for battery usage

Export getting icon and name function as static method in the
BatteryEntry for further restoring from database history records, and
export the mBatteryConsumer to record the type into local database.

Bug: 183906918
Test: make RunSettingsRoboTests
Test: make RunSettingsGoogleRoboTests
Change-Id: Ib3f0a457c8265baf0f6b97798bef0ea4a7156070