Switch horizon to direct upload mode to glance

This patch switches horizon to direct upload mode to glance.
It will prevent horizon from caching user image on proxy node.

Disable caching for glance site on proxy node.

Enable CORS in glance with allowed origins set to horizon URL.

Parametrize horizon proxy settins:
 * horizon_public_host
 * horizon_public_port
 * horizon_public_protocol
 
 Related-Prod: PROD-24536

Change-Id: Ie2ff8b58c352584d076e0c85bd033dc8fe52ee89
diff --git a/nginx/server/proxy/openstack/glance.yml b/nginx/server/proxy/openstack/glance.yml
index 9cdd702..d8ef4a5 100644
--- a/nginx/server/proxy/openstack/glance.yml
+++ b/nginx/server/proxy/openstack/glance.yml
@@ -20,6 +20,8 @@
             port: 9292
             protocol: ${_param:nginx_proxy_openstack_glance_protocol}
             size:  ${_param:nginx_proxy_openstack_glance_image_size}
+            # Prevent nginx from caching request body
+            request_buffer: false
           host:
             name: ${_param:nginx_proxy_openstack_api_host}
             port: 9292