docker2podman: use set_fact to override variables

play vars have lower precedence than role vars and `set_fact`.
We must use a `set_fact` to reset these variables.

Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>
(cherry picked from commit b0c491800a)

infrastructure-playbooks/docker-to-podman.yml

@@ -47,12 +47,6 @@
     - "{{ iscsi_gw_group_name | default('iscsigws') }}"
     - "{{ rbdmirror_group_name | default('rbdmirrors') }}"
   become: true
-  vars:
-    docker2podman: True
-    container_binary: podman
-    container_binding_name: podman
-    container_service_name: podman
-    container_package_name: podman
   pre_tasks:
     - import_role:
         name: ceph-defaults
@@ -73,6 +67,14 @@
 
 
   tasks:
+    - name: set_fact container_binary, container_binding_name, container_service_name, container_package_name
+      set_fact:
+        docker2podman: True
+        container_binary: podman
+        container_binding_name: podman
+        container_service_name: podman
+        container_package_name: podman
+
     - name: install podman
       package:
         name: podman