Apply the correct image reference when booting an instance

We seem to be using the Nova's defaults instead. Also verify that the
resulting image type in instance_info is correct.

Depends-On: https://review.opendev.org/c/openstack/ironic/+/827882
Change-Id: Iaba563a2ecbca029889bc6894b2a7f0754d27b88
2 files changed