Marker issue with sanitization

STR:

1. open [this profile](https://profiler.firefox.com/public/j0t9bq5w2cseghhfan646t8dg6kdcmm0edn2sz8/marker-chart/?globalTrackOrder=0&localTrackOrderByPid=30923-1-2-0~&markerSearch=UserTiming&range=m5028&thread=0&v=5)
1. publish it, by _removing_ the hidden time range

=> notice how the activity graph at the top doesn't change, BUT the markers at the bottom change. Also notice how the times in the top bar changed.

After publishing, you can "revert", and you can notice that the top timeline stay the same as in the "sanitized" version (so it's different than before)... but otherwise the activity graph and the marker chart are like before the publishing.

┆Issue is synchronized with this [Jira Task](https://mozilla-hub.atlassian.net/browse/FP-347)