Use listen instead of chained notifiers

From Ansible 2.2 onwards, listen can be used for
handlers instead of chaining notifiers. The
handlers are then executed in the sequence
present in the handler file.

Change-Id: I34312074ed2ab298111831fb5e1640d6a7ec77f5

handlers/main.yml

@@ -13,13 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-- name: Restart aodh services
-  command: "/bin/true"
-  notify:
-    - Stop services
-    - Copy new policy file into place
-    - Start services
-
 - name: Stop services
   service:
     name: "{{ item.service_name }}"
@@ -31,6 +24,7 @@
   until: _stop | success
   retries: 5
   delay: 2
+  listen: Restart aodh services
 
 # Note (odyssey4me):
 # The policy.json file is currently read continually by the services
@@ -48,6 +42,7 @@
     group: "{{ aodh_system_group_name }}"
     mode: "0640"
     remote_src: yes
+  listen: Restart aodh services
 
 - name: Start services
   service:
@@ -60,6 +55,7 @@
   until: _start | success
   retries: 5
   delay: 2
+  listen: Restart aodh services
 
 - name: Restart web server
   service: