Add autopkgtests to parse the profiles installed by this package, to ensure...

Add autopkgtests to parse the profiles installed by this package, to ensure that parser and abstraction updates don't break them (Closes: #866368).

That's basically the same tests we run at build time already (see
override_dh_auto_test); they don't mess with the kernel, and don't require
AppArmor to be enabled.

debian/tests/control

+Tests: test-installed
+Depends: @
+Restrictions: allow-stderr

debian/tests/test-installed

+#!/bin/sh
+
+set -e
+set -u
+set -x
+
+PROFILES_NAMES=$(find profiles -maxdepth 1 -type f -printf '%f\n')
+
+for profile_name in $PROFILES_NAMES ; do
+   echo "Testing $profile_name"
+   /sbin/apparmor_parser \
+       --add \
+       --skip-cache \
+       --skip-kernel-load \
+       "/etc/apparmor.d/$profile_name"
+done