Add ability set volume_device_name parameter value

Implicit default in nova-compute.conf template in nova salt formula
for nova.compute.config_drive.forced is 'true', so that we should
change volume_device_name parameter value from default(vdb)
on custom(vdc).

Change-Id: I5a4c4d20bae90173724f5a7ceaea972c4b91ed63
Related-prod: PROD-21352
1 file changed