Merge "Import wifi_channel_stat into legacy_hal namespace." am: 9883e2fc46 am: 273d2dd6e7

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1559106

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I98de8d18bc94ce651db51fdebba9aeb8132798ca