sepolicy: /dev/dri/* access to mediaserver for video playback am: c717c467fb am: dfd8a5385a am: 229729cc2b

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/1345438

Change-Id: I8d3b0163c021b90551fc266f7227156cc812f8a1