dragonboard: sepolicy: Add sepolicy rules to fix problems seen adb remount overlays am: a58e74ea06 am: 2372d29d25

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/2063214

Change-Id: I365ed760128b0ba6ff95d421ae4b4efafd355132
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>