Add owners for record protos

Bug: chromium:1078512
Change-Id: I96ecb2bd4a8a41cf8d55ce1c0f041999115389db
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2302717Reviewed-by: Sergey Poromov <poromov@chromium.org>
Commit-Queue: Zach Trudo <zatrudo@google.com>
Cr-Commit-Position: refs/heads/master@{#790886}

components/policy/proto/OWNERS

+per-file record*=zatrudo@google.com
+per-file record*=lbaraz@chromium.org