Incorrect selected range after sharing a profile without hidden threads.

Steps to reproduce:

1. Capture or load a profile that has 2 processes that start having samples at different times (this can often happen if one process is very active and uses its buffer space quickly, and another one is idle). Example: https://share.firefox.dev/3jpOaiI
1. In this profile, select only the tracks that start later (eg, show only the 'Socket process' group in the previous profile). Result: https://share.firefox.dev/3kuyMko
1. Zoom into the part of the profile that has samples. Result: https://share.firefox.dev/3zxNE7R (a 13s range)
1. Re-upload the profile with the "Include hidden threads" unchecked. (Broken) result: https://share.firefox.dev/3yzrIbm This shows a 21s range out of a 13.s profile.

┆Issue is synchronized with this [Jira Task](https://mozilla-hub.atlassian.net/browse/FP-430)