Add demo apps disclaimer to Demo Mode ARC++ setup

Bug: 945438
Change-Id: I314f5aecb5e12fa17fc033b51af0305c80039b47
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1568310
Reviewed-by: Toni Baržić <tbarzic@chromium.org>
Reviewed-by: Aga Wronska <agawronska@chromium.org>
Commit-Queue: Michael Giuffrida <michaelpg@chromium.org>
Auto-Submit: Michael Giuffrida <michaelpg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652626}
6 files changed