mm: allow access page_owner in debugfs am: 8724397535 am: 669685b4c0 am: af42d3cd3d am: 6a8960819e

Original change: https://android-review.googlesource.com/c/platform/hardware/google/pixel-sepolicy/+/1430211

Change-Id: I9cb0dab3cc34654ea8bba55c5efb8a8ebfdd9b63