Add configuration option 'image_conversion_dir' for cinder.

Cinder configuration option 'image_conversion_dir' set path to directory
used for temporary storage during image conversion.

Change-Id: Icc01549730e6b9457a88cd933b877e9968384775
Related-Prod: PROD-29437 (PROD:29437)
(cherry picked from commit edaf7481d5616bd905911c502a070b6b45a69fa1)
diff --git a/defaults/openstack/init.yml b/defaults/openstack/init.yml
index 14160e7..4b1960d 100644
--- a/defaults/openstack/init.yml
+++ b/defaults/openstack/init.yml
@@ -44,6 +44,7 @@
     cinder_version: ${_param:openstack_version}
     cinder_upgrade_enabled: ${_param:openstack_upgrade_enabled}
     cinder_service_user_enabled: ${_param:openstack_service_user_enabled}
+    cinder_image_conversion_dir_path: /var/tmp/cinder/conversion
     # Nova
     nova_memcache_security_enabled: ${_param:openstack_memcache_security_enabled}
     nova_memcache_secret_key: ''