Fix inline sessions for webxr samples

Inline sessions with options now require user activation or they are
rejected.  This changes pages with inline sessions to default request
an inline session without any options and to request the options in a
tap gesture (since Android is currently the only platform that really
supports modes other than viewer)

Bug: 1005159
Change-Id: Ia6941200d14c29f962f95cd5bfe9b662a9b0eec8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1810757
Auto-Submit: Alexander Cooper <alcooper@chromium.org>
Commit-Queue: Jacob DeWitt <jacde@chromium.org>
Reviewed-by: Jacob DeWitt <jacde@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697645}
14 files changed