docker: introduce use_crio_only

Introduce a new variable that disable the installation of Docker.  For
the time being we will still need Docker for building images, so by
default leave it installed.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

roles/docker/tasks/main.yml

@@ -8,18 +8,19 @@
 - set_fact:
     l_use_system_container: "{{ openshift.docker.use_system_container | default(False) }}"
     l_use_crio: "{{ openshift.docker.use_crio | default(False) }}"
+    l_use_crio_only: "{{ openshift.docker.use_crio_only | default(False) }}"
 
 - name: Use Package Docker if Requested
   include: package_docker.yml
   when:
   - not l_use_system_container
-  - not l_use_crio
+  - not l_use_crio_only
 
 - name: Use System Container Docker if Requested
   include: systemcontainer_docker.yml
   when:
   - l_use_system_container
-  - not l_use_crio
+  - not l_use_crio_only
 
 - name: Add CRI-O usage Requested
   include: systemcontainer_crio.yml