Add fixed_key parameter under key_manager section in cinder conf

This change is necessary for uploading an encrypted volume to glance.

Change-Id: I0975fc0c49ec243025d076f0406e28c4f5522d3a
diff --git a/lib/cinder b/lib/cinder
index 07f82a1..a966a4b 100644
--- a/lib/cinder
+++ b/lib/cinder
@@ -244,6 +244,7 @@
     iniset $CINDER_CONF DEFAULT my_ip "$HOST_IP"
 
     iniset $CINDER_CONF key_manager backend cinder.keymgr.conf_key_mgr.ConfKeyManager
+    iniset $CINDER_CONF key_manager fixed_key $(openssl rand -hex 16)
 
     if is_service_enabled c-vol && [[ -n "$CINDER_ENABLED_BACKENDS" ]]; then
         local enabled_backends=""