Add timestamp to the etw event payload

TraceEvents contain a timestamp which is meaningful for events that have
a start/stop time or a duration.  This change ensures the timestamp is
included in the etw event payload.

Bug: 1451241
Change-Id: I24b1a95d3190ef05f7fff2c63f0ab7b2fe35fff0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4883752
Commit-Queue: Chris Davis <chrdavis@microsoft.com>
Reviewed-by: Etienne Pierre-Doray <etiennep@chromium.org>
Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1200324}