undercloud-upgrade jobs on master fails on validation.

Hi,

tripleo-ci-centos-7-containerized-undercloud-upgrades fails on master, as seen there, http://zuul.openstack.org/builds?job_name=tripleo-ci-centos-7-containerized-undercloud-upgrades.

Checking one log give that error: https://zuul.opendev.org/t/openstack/build/612b37310cb940f1b55a306daa34c47b/log/job-output.txt#5384-5395

2019-08-22 10:35:09.822312 | primary | TASK [validate-services : Fails if we find failed systemd units] ***************

2019-08-22 10:35:09.848295 | primary | Thursday 22 August 2019 10:35:09 +0000 (0:00:00.141) 0:00:08.033 *******

2019-08-22 10:35:09.906893 | primary | fatal: [undercloud]: FAILED! => {

2019-08-22 10:35:09.907129 | primary | "assertion": "systemd_state.stdout_lines|length == 0",

2019-08-22 10:35:09.907215 | primary | "changed": false,

2019-08-22 10:35:09.907301 | primary | "evaluated_to": false

2019-08-22 10:35:09.907343 | primary | }

2019-08-22 10:35:09.907382 | primary |

2019-08-22 10:35:09.907428 | primary | MSG:

2019-08-22 10:35:09.907466 | primary |

2019-08-22 10:35:09.907535 | primary | Assertion failed

2019-08-22 10:35:09.929052 | primary |

We have to check if that validation error is valid.