When we change the version number in metrics_utils:

If the user is not a Googler, or has opted out explicitly, nothing happens
and we still don't collect metrics.

If we're collecting metrics from the user, we stop collecting metrics
and display a notice telling them what has changed.
That notice will be displayed ten times, after which we will
resume collecting metrics. A notice telling them we're collecting metrics
will still be displayed.

Bug: None
Change-Id: If1cc12b2fc06f0d6237714c4f182367b1afdf9fb
Reviewed-on: https://chromium-review.googlesource.com/c/1285395
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>