components/arc/video_accelerator: add OWNERS

Add the current ARC++ video team member to the OWNERS.

BUG=None
TEST=None

Change-Id: I502e3445104efe5327d2a780e29d8ca934ea4696
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2377183Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Commit-Queue: Chih-Yu Huang <akahuang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#802095}

components/arc/video_accelerator/OWNERS

+akahuang@chromium.org
+acourbot@chromium.org
+dstaessens@chromium.org
 hiroh@chromium.org
 kcwu@chromium.org
 posciak@chromium.org