Do not use ‘yes/no’ for boolean values (#11472)

Consistent boolean values in ansible playbooks

roles/adduser/defaults/main.yml

@@ -7,14 +7,14 @@ addusers:
   etcd:
     name: etcd
     comment: "Etcd user"
-    create_home: no
-    system: yes
+    create_home: false
+    system: true
     shell: /sbin/nologin
   kube:
     name: kube
     comment: "Kubernetes user"
-    create_home: no
-    system: yes
+    create_home: false
+    system: true
     shell: /sbin/nologin
     group: "{{ kube_cert_group }}"