CRAS: add dup to seccomp policies

Creating a client-provided shm stream calls dup, so add it to the
seccomp policies.

BUG=chromium:968724
TEST=cq

Change-Id: Ieba0842079842d2c6488092eaf79a1a8cb131af3
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/adhd/+/1806144
Tested-by: Fletcher Woodruff <fletcherw@chromium.org>
Commit-Queue: Fletcher Woodruff <fletcherw@chromium.org>
Reviewed-by: Chih-Yang Hsia <paulhsia@chromium.org>
3 files changed