Comment 3 for bug 1821920

It looks like the change mentioned in the above comment came from Debian. Here's the commit:

  https://salsa.debian.org/apparmor-team/apparmor/commit/dc14f24b2c2943c29d0368f913020f1307d8f1d3

They obviously don't have <abstractions/ubuntu-browsers.d/*> so they opted to remove that logic from the postinst. I think we should have kept it during our merge.