vr: Amend OWNERs and remove vr_shell noparent

BUG=

Change-Id: I71fd5ed6623499c55332e3ccc3372123768d37c8
Reviewed-on: https://chromium-review.googlesource.com/579689


Reviewed-by: Ian Vollick <vollick@chromium.org>
Commit-Queue: Christopher Grant <cjgrant@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488325}