Revise/add correct manila service type
Revise/add correct manila service type

This fixes the previous change, and adds service type and Charm
consistent descriptions, derived from:
http://docs.openstack.org/developer/manila/adminref/quick_start.html

Change-Id: Id750c174ff33186ea387d7cca6dcef6b69fc25c4

coreycb/charm-keystone,coreycb/charm-keystone