etcd runtime: system container can be etcd too

roles/etcd/tasks/runtime.yml

@@ -8,7 +8,12 @@
 - name: Set runtime to host
   set_fact:
     r_etcd_common_etcd_runtime: host
-  when: etcd_service.status.ActiveState == 'active'
+  when: etcd_service.status.ActiveState == 'active' and not l_is_etcd_system_container
+
+- name: Set runtime to runc
+  set_fact:
+    r_etcd_common_etcd_runtime: runc
+  when: etcd_service.status.ActiveState == 'active' and l_is_etcd_system_container
 
 - name: Check if etcd service exists
   systemd: