Set Ceph pools rule_name to replicated_rule

By setting the value of rule_name explicitly, we prevent backward
incompatibility issues because the default which ceph-ansible uses
might fit a particular version of Ceph, not all.

Change-Id: I275c1ca53ea79eea607cbbb58aa21cae6d6be80b
Closes-Bug: 1776252

ci/environments/scenario001-multinode-containers.yaml

@@ -124,7 +124,7 @@ parameter_defaults:
   CephPools:
     - name: altrbd
       pg_num: 8
-      rule_name: ''
+      rule_name: replicated_rule
   CephAnsibleExtraConfig:
     centos_package_dependencies: []
     ceph_osd_docker_memory_limit: '1g'

docker/services/ceph-ansible/ceph-base.yaml

@@ -83,7 +83,7 @@ parameters:
     description: >
       It can be used to override settings for one of the predefined pools, or to create
       additional ones. Example:
-      [{"name": "volumes", "pg_num": 64, "rule_name": ""}]
+      [{"name": "volumes", "pg_num": 64, "rule_name": "replicated_rule"}]
     default: []
     type: json
   CinderRbdPoolName:
@@ -226,7 +226,7 @@ resources:
                       template:
                         name: <%pool%>
                         pg_num: {get_param: CephPoolDefaultPgNum}
-                        rule_name: ""
+                        rule_name: replicated_rule
                         application: rbd
                       for_each:
                         <%pool%>:
@@ -242,7 +242,7 @@ resources:
                     - []
                     - - name: {get_param: GnocchiRbdPoolName}
                         pg_num: {get_param: CephPoolDefaultPgNum}
-                        rule_name: ""
+                        rule_name: replicated_rule
                         application: openstack_gnocchi
                   - {get_param: CephPools}
           openstack_keys: &openstack_keys