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>
(cherry picked from commit de1d9df7)

Conflicts:
	roles/etcd/tasks/check_certs.yml