Refactor NRI (Node Resource Interface) activation in CRI-O and
containerd. Introduce a shared variable, nri_enabled, to streamline
the process. Currently, enabling NRI requires a separate update of
defaults for each container runtime independently, without any
verification of NRI support for the specific version of containerd
or CRI-O in use.

With this commit, the previous approach is replaced. Now, a single
variable, nri_enabled, handles this functionality. Also, this commit
separates the responsibility of verifying NRI supported versions of
containerd and CRI-O from cluster administrators, and leaves it to
Ansible.

Signed-off-by: Feruzjon Muyassarov <feruzjon.muyassarov@intel.com>