I don't believe this is due to apparmor. However there certainly is an apparmor bug, as running virsh snapshot-create-as causes the /etc/apparmor.d/libvirt/<test1-uuid>.files entry for /var/lib/libvirt/images/test1.img to be replaced by one for
/var/lib/libvirt/images/test1.snapshot1
I don't believe this is due to apparmor. However there certainly is an apparmor bug, as running virsh snapshot-create-as causes the /etc/apparmor. d/libvirt/ <test1- uuid>.files entry for /var/lib/ libvirt/ images/ test1.img to be replaced by one for
/var/lib/ libvirt/ images/ test1.snapshot1