[Trusted Types] Add renderer/core/trustedtypes/OWNERS

Bug: 739170
Change-Id: Ia158d98717cf0360870f46eeabca0777b1954ec1
Reviewed-on: https://chromium-review.googlesource.com/1243143Reviewed-by: Mike West <mkwst@chromium.org>
Commit-Queue: Daniel Vogelheim <vogelheim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595439}

third_party/blink/renderer/core/trustedtypes/OWNERS

+mkwst@chromium.org
+vogelheim@chromium.org
+
+# COMPONENT: Blink>SecurityFeature