media/test/data: Create OWNERS and Add permission to media/gpu/OWNERS

BUG=None
TEST=None

Change-Id: Idead4ef4897465c6e9950cac26859d548b326289
Reviewed-on: https://chromium-review.googlesource.com/1039111Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Hirokazu Honda <hiroh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#555602}

media/test/data/OWNERS

+file://media/gpu/OWNERS