Configure Horizon timezone according to the host timezone

Timezone configuration in Horizon should have the same as the one
in the controller hosts.
This patch makes tripleo-heat-templates to pass the TimeZone option
also for horizon configuration, so that we can have the proper
value configured in local_settings.

Change-Id: I39bc75b164f85cd296a7b6b3c454a172338af9cb

deployment/horizon/horizon-container-puppet.yaml

@@ -98,6 +98,10 @@ parameters:
     default: ''
     description: Horizon has a global overrides mechanism available to perform customizations
     type: string
+  TimeZone:
+    default: 'UTC'
+    description: The timezone to be set on the overcloud.
+    type: string
   WebSSOEnable:
     default: false
     type: boolean
@@ -179,6 +183,7 @@ outputs:
           horizon::listen_ssl: {get_param: EnableInternalTLS}
           horizon::horizon_ca: {get_param: InternalTLSCAFile}
           horizon::customization_module: {get_param: HorizonCustomizationModule}
+          horizon::timezone: {get_param: TimeZone}
         -
           if:
           - websso_enabled