Upgrade the pinned AppArmor feature set for Buster
Originally created by @intrigeri on #15149 (Redmine)
If we’re still shipping our own
config/chroot_local-includes/etc/apparmor/features
(that is, probably
only if https://bugs.debian.org/882697 is not fixed in Stretch) we
shall upgrade it, or more likely drop it (assuming the apparmor package
shipped in Buster includes its own pinned feature set).