apparmor: allow openGraphicsFD for virt manager >1.4
virt-manager's UI connection will need socket access for openGraphicsFD
to work - otherwise users will face a failed connection error when
opening the UI view.
Depending on the exact versions of libvirt and qemu involved this needs
either a rule from qemu to libvirt or vice versa.
Acked-by: Jamie Strandboge <jamie@canonical.com> Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>