[automerger skipped] power/stats: Adding subsystem field to Channel am:...

[automerger skipped] power/stats: Adding subsystem field to Channel am: e3dfa5b1 am: 4c23c689 am: 0de05e24 -s ours

am skip reason: Change-Id I630d26ffe02e7d8a26f42f10516900370db3a3bb with SHA-1 d9a671e6 is in history

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1576531

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ib4b97521db8d357886036d8144d2a2294a09cbf1