undercloud oooq subunit file creation creates default failures and should be skipped

[wes hayutin]

ATM the tripleo-ui jobs which run the generate-subunit command are generating by default failing results. The subunit file is never overwritten by tempest or the ping test

This results in the job showing up as 100% failing in openstack health [1]

http://logs.openstack.org/90/515990/6/gate/legacy-tripleo-ci-centos-7-undercloud-oooq/1b8b85f/job-output.txt.gz#_2017-11-02_09_25_48_289853

To-fix:
skip the generation of the subunit file for the undercloud only installs

[1] http://status.openstack.org/openstack-health/#/g/project/openstack~2Ftripleo-ui

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/517657

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/518118

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/517657
Committed: https://git.openstack.org/cgit/openstack/tripleo-quickstart-extras/commit/?id=42d71884f91f76c4e6bf50d500ca798d931387f3
Submitter: Zuul
Branch: master

commit 42d71884f91f76c4e6bf50d500ca798d931387f3
Author: Wes Hayutin <email address hidden>
Date: Fri Nov 3 13:05:56 2017 -0400

    create subunit test results for the undercloud sanity check

    In OpenStack health all the tests are marked as failures
    because by default we create a failing subunit result
    for all jobs. We need to create results for the undercloud.

    Related-Bug: #1729686
    Change-Id: I4850eaadc09035577cb48a367c5f482ed07b7a32