about:preferences Change Block List contains an occurrence of "Firefox"
This is a spinoff from #27905 (moved). There is an occurrence of
Firefox within the about:preferences
Change Block List "dialog" which was fixed in Firefox 61 to pull the product name from
brandShortName. Since it will not be easy to backport the fix to ESR60, we will pick this up with ESR68 (see https://hg.mozilla.org/mozilla-central/rev/8ebf84e9825d).