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: Ia185ab830005f311f37d4eb7dfab1ae116419e3b
(cherry picked from commit af9142ec9b)

handlers/main.yml

@@ -13,13 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-- name: Restart glance 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 glance services"
 
 # Note (odyssey4me):
 # The policy.json file is currently read continually by the services
@@ -48,6 +42,7 @@
     group: "{{ glance_system_group_name }}"
     mode: "0640"
     remote_src: yes
+  listen: "Restart glance services"
 
 - name: Start services
   service:
@@ -60,3 +55,4 @@
   until: _start | success
   retries: 5
   delay: 2
+  listen: "Restart glance services"