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

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

Change-Id: I2e486686e8902de4111ec97541e8c3014f8c1224