Add GPU FYI XR Win Builder

Adds the LUCI and mb config changes for the new XR Win Builder on
chromium.gpu.fyi.

Bug: 939185
Change-Id: I085f108b6eec7f90f8bb899777de505cfa1457cd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1620526
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661468}
4 files changed