Currently, unit testcases of virt emit FutureWarnings
from oslo.versionedobjects about invalid uuids as documented here[1].
This commit changes these tests to use valid uuids so
that when they are run these warnings are no longer emitted.
Fake constants are defined for project_id and user_id as they
are used without '-' at keystone side.
[1] http://docs.openstack.org/developer/oslo.versionedobjects/api/fields.html#oslo_versionedobjects.fields.UUIDField
Partial-Bug: #1557378
Change-Id: If69412eddb5e64cb8ccc5dce9176d19382c0b3f1