tests: skip tests when xatts are not supported
tests: skip tests when xatts are not supported

Signed-off-by: Christian Brauner <48455ab3070520a2d174545c7239d6d0fabd9a83@canonical.com>

lxc/lxd,mjeanson/lxd,stgraber/lxd,pcdummy/lxd,mjeanson/lxd,hallyn/lxd,stgraber/lxd,chrisglass/lxd,atxwebs/lxd,Skarlso/lxd,lxc/lxd,erikmack/lxd,akshaykarle/lxd,ollie314/lxd,Skarlso/lxd,georghopp/lxd,lxc/lxd,techtonik/lxd,stgraber/lxd,atxwebs/lxd,stgraber/lxd,lxc/lxd,georghopp/lxd,lxc/lxd,techtonik/lxd,erikmack/lxd,hallyn/lxd,georghopp/lxd,pcdummy/lxd,lxc/lxd,pcdummy/lxd,atxwebs/lxd,chrisglass/lxd,jsavikko/lxd,akshaykarle/lxd,akshaykarle/lxd,mjeanson/lxd,jsavikko/lxd,erikmack/lxd,hallyn/lxd,ollie314/lxd,stgraber/lxd,lxc/lxd,Skarlso/lxd,Skarlso/lxd,jsavikko/lxd,hallyn/lxd,stgraber/lxd,ollie314/lxd,atxwebs/lxd,hallyn/lxd,chrisglass/lxd,techtonik/lxd,hallyn/lxd,stgraber/lxd