OWNERS: clarify top-level reviewer expectations

BUG=None
TEST=CQ passes

Change-Id: I99e8ff0f15b5929552115b6119ffa7426ea9366b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/3774578
Auto-Submit: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Ram Chandrasekar <rchandrasekar@google.com>
Reviewed-by: Ram Chandrasekar <rchandrasekar@google.com>
1 file changed