Move PowerStats service sepolicy to powerstats am: 041f4263d1 am: fa8bc7c2dc am: 4154d58a62 am: ecb8d4e1f5

Original change: https://android-review.googlesource.com/c/platform/hardware/google/pixel-sepolicy/+/1428229

Change-Id: Ib07134f6f953634a8ba654403dc7e3d836bada1b