Wipe BatteryStats on Custom Power Bucket change

If the supported OTHER EnergyConsumers change after a reboot, the
MeasuredEnergyStats from the reboot can no longer be considered valid.

Bug: 178504428
Test: atest FrameworksCoreTests:com.android.internal.power.MeasuredEnergyStatsTest
Change-Id: I2561c459c0b2a881661bd2913f9413a2cbd96abb