/etc/apparmor.d/program-chunks/postfix-common is in apparmor-profiles 2.7.103-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | # ------------------------------------------------------------------
#
#    Copyright (C) 2002-2005 Novell/SUSE
#
#    This program is free software; you can redistribute it and/or
#    modify it under the terms of version 2 of the GNU General Public
#    License published by the Free Software Foundation.
#
# ------------------------------------------------------------------
# used with postfix/*
  capability            setuid,
  capability            setgid,
  capability            sys_chroot,
  /etc/postfix/*.cf     r,
  /etc/postfix/*.db     r,
  @{PROC}/net/if_inet6  r,
  /usr/lib/postfix/*.so mr,
  /usr/lib64/sasl2/*    mr,
  /usr/lib64/sasl2/     r,
  /usr/lib/sasl2/*      mr,
  /usr/lib/sasl2/       r,
 |