Enable cpp support for IPowerStats AIDL interface am: 5aae5cb79d am: 6e92dab27b

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1628872

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Iee49696003865dc3f10b1107313f6d77b3980b7e