This change replaces invalid UUIDs used in unit tests which are causing
the deprecation warnings like;
FutureWarning: b"'fake_volume_id'" is an invalid UUID. Using UUIDFields
with invalid UUIDs is no longer supported, and will be removed in
a future release. Please update your code to input valid UUIDs or
accept ValueErrors for invalid UUIDs. ...
Change-Id: I18b0a7c81efd8fe981bdd7a3c41a7044147a96a0