Missing usr.sbin.mysqld AppArmor profile

This package is missing the usr.sbin.mysqld AppArmor profile that ships in mariadb-server-10.0 and mysql-server-5.7.

As a result in case of a pxc being installed on a server that previously had either of those packages installed, /usr/sbin/mysqld is unable to create files in /var/lib/percona-xtradb-cluster/, and the service is unable to start.

Sep 15 14:15:56 ubuntu systemd[1]: Starting LSB: Start and stop the mysql (Percona XtraDB Cluster) daemon...
Sep 15 14:15:56 ubuntu mysql[31797]: * Starting MySQL (Percona XtraDB Cluster) database server mysqld
Sep 15 14:15:56 ubuntu /etc/init.d/mysql[31835]: MySQL PID not found, pid_file detected/guessed: /var/run/mysqld/mysqld.pid
Sep 15 14:15:57 ubuntu kernel: [43130.482986] audit: type=1400 audit(1473948957.156:42): apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/var/lib/percona-xtradb-cluster/daisy.lower-test" pid=32173 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=0 ouid=0
Sep 15 14:15:57 ubuntu kernel: [43130.483012] audit: type=1400 audit(1473948957.156:43): apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/var/lib/percona-xtradb-cluster/daisy.lower-test" pid=32173 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=0 ouid=0
Sep 15 14:15:57 ubuntu kernel: [43130.499375] audit: type=1400 audit(1473948957.172:44): apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/var/lib/percona-xtradb-cluster/ibdata1" pid=32173 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=113 ouid=113
Sep 15 14:15:57 ubuntu mysql[31797]: * The server quit without updating PID file (/var/run/mysqld/mysqld.pid).
Sep 15 14:15:57 ubuntu mysql[31797]: ...fail!
Sep 15 14:15:57 ubuntu systemd[1]: mysql.service: Control process exited, code=exited status=1
Sep 15 14:15:57 ubuntu systemd[1]: Failed to start LSB: Start and stop the mysql (Percona XtraDB Cluster) daemon.

Workarounds:

- reload all AA profiles, removing AA protection for /usr/sbin/mysqld
- copy /etc/apparmor.d/usr.sbin.mysqld over from mariadb-server-10.0 or mysql-server-5.7, AND fix the datadir (as pxc uses /var/lib/percona-xtradb-cluster, rather than /var/lib/mysql).

Permanent fix:

- ship /etc/apparmor.d/usr.sbin.mysqld within the percona-xtradb-cluster-server package