IronicDriver uses instance_id instead of instance_uuid in fields when calling Ironic API

[Dustin Cowles]

Description
===========
IronicDriver should be using fields="instance_uuid" when calling Ironic API via the OpenStack SDK, but instead is using fields="instance_id". The SDK will return a node object with node.instance_id, which lead to the confusion in implementation.

References
==========
[1] https://review.opendev.org/#/c/656027/29/nova/virt/ironic/driver.py@690
[2] https://logs.rdoproject.org/openstack-periodic-master/opendev.org/openstack/tripleo-ci/master/periodic-tripleo-ci-centos-7-ovb-3ctlr_1comp-featureset001-master/62c604a/logs/undercloud/var/log/containers/nova/nova-compute.log.txt.gz#_2019-09-05_03_24_13_909
[3] https://logs.rdoproject.org/openstack-periodic-master/opendev.org/openstack/tripleo-ci/master/periodic-tripleo-ci-centos-7-ovb-1ctlr_2comp-featureset020-master/2b85de7/logs/undercloud/var/log/extra/errors.txt.txt.gz#_2019-09-05_02_41_26_036
[4] https://github.com/openstack/openstacksdk/blob/master/openstack/baremetal/v1/node.py#L96

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/680542

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/680542
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=19f01023c23b793388d693b7272cac799b5b6ff8
Submitter: Zuul
Branch: master

commit 19f01023c23b793388d693b7272cac799b5b6ff8
Author: Dustin Cowles <email address hidden>
Date: Thu Sep 5 16:48:38 2019 -0700

    Use fields="instance_uuid" when calling Ironic API

    IronicDriver should be using fields="instance_uuid" when calling Ironic
    API via the OpenStack SDK, but instead is using fields="instance_id".
    This patch corrects the calls and adds new tests to cover it.

    Change-Id: I4b976b7ea60c63ec334b5eb78c1ad7972fbed574
    Closes-Bug: #1842989

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/nova 20.0.0.0rc1 release candidate.