Only use stat get_checksum: yes when needed (#7270)

By default Ansible stat module compute checksum, list extended attributes and find mime type
To find all stat invocations that really use one of those:
git grep -F stat. | grep -vE 'stat.(islnk|exists|lnk_source|writeable)'

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

roles/container-engine/docker/tasks/main.yml

@@ -2,6 +2,9 @@
 - name: check if fedora coreos
   stat:
     path: /run/ostree-booted
+    get_attributes: no
+    get_checksum: no
+    get_mime: no
   register: ostree
 
 - name: set is_ostree