Limit collectds memory usage in the ansible part

In analogy to I0b65b2c7878fe5ebd0d7f1a6f2ba8df23f2f0b28
where the memory was limited in the puppet part

Change-Id: I83a245b51dd58457001e82e0ee5b04c1fc6de2ac
(cherry picked from commit c25eec5bff)

deployment/metrics/collectd-container-ansible.yaml

@@ -397,6 +397,7 @@ outputs:
             pid: host
             user: root
             restart: always
+            mem_limit: 512m
             cap_add:
               list_concat:
                 - {get_param: CollectdContainerAdditionalCapAdd}