Because ansible_distribution_version doesn't return minor version on
CentOS with ansible 2.8 we can apply the selinux anyway but only for
CentOS/RHEL 7.
Starting RHEL 8, there's a dedicated package for selinux called
nfs-ganesha-selinux [1].
Also replace the command module + semanage by the selinux_permissive
module.