apparmor: Fix loading multiple profiles

apparmor's systemd service wasn't working when multiple profiles were
defined, due to the ExecStart commands in the service file being
broken into multiple lines, instead of being separated by ';'.
apparmor: Fix service stop

When stopping the apparmor service, the profile removal failed with
parsing errors due to not including the
${pkgs.apparmor}/etc/apparmor.d directory.
Merge pull request #173 from wizeman/apparmor-service

Apparmor service fixes