This patch adds a feature by which we allow setting default volume types
for projects.
The following changes are made to achieve the feature:
1) Add 4 set of APIs, set, get, get_all, unset volume type
2) All policies (except get_all) default to system/domain/project admin
3) Preference order: project default, conf default
4) Logic to not allow deletion of default type
We validate set, get and unset APIs with keystone to verify a valid
project id is passed in the request and user has proper authorization
rights to show the project.
The policies are system/domain/project admin by default except get_all
policy which defaults to system admin.
Implements: Blueprint multiple-default-volume-types
Change-Id: Idcc949ed6adbaea0c2337fac83014998b81ff1f8
e63cb8548a