OS_REGION_NAME mishandling in subcloud name reconfiguration implementation

[Cristian Mondo]

Brief Description
-----------------

DM is unable to apply due to corrupt deployment-config.yaml

the metioned file only contains OS_REGION_NAME:

Severity
---------

is imposible to deploy subclouds

<Critical: System/Feature is not usable after the defect>

Steps to Reproduce
-----------------

install system controller with latest load
upload deploy files
perform subcloud add
Expected Behavior

Subcloud is deployed successfully

Actual Behavior
-----------------

subcloud deployment fails at DM apply stage

Reproducibility
-----------------

Reproducible 100%

System Configuration
-----------------

DC

Last Pass
----------

Timestamp/Logs
-----------------

TASK [Fail if config file failed to apply] *************************************
Monday 18 September 2023 22:39:38 +0000 (0:00:53.431) 0:16:31.958 ******
fatal: [subcloud1]: FAILED! => changed=false
  msg:
  - Failed to apply DM config file
  - 'Check syntax into config file. See documentation examples. '
  - Err_code= dm_apply_failed
  - 'Config file error: error: error validating "/home/sysadmin/deployment-config.yaml": error validating data: [apiVersion not set, kind not set]; if you choose to ignore these errors, turn validation off with --validate=false'

Alarms
------

no alarms present

Test Activity
-----------------

Feature Testing Subcloud Name Reconfiguration

Workaround
-----------

N/A

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/distcloud/+/895850

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/distcloud/+/895850
Committed: https://opendev.org/starlingx/distcloud/commit/4ed1f39731689f95947e3b64aee371378b7e6b29
Submitter: "Zuul (22348)"
Branch: master

commit 4ed1f39731689f95947e3b64aee371378b7e6b29
Author: Cristian Mondo <email address hidden>
Date: Tue Sep 19 12:03:10 2023 -0300

    Fix to prevent mishandling of OS_REGION_NAME

    With the Subcloud Rename Feature, a mechanism was introduced in
    dcmanager, when the deployment file is uploaded, to modify the
    OS_REGION_NAME prior to send it to the subcloud, required for
    the installation of the Deployment.

    Doing this manipulation of the deployment file on the dcmanager
    site generates confusion for the handling of the required
    OS_REGION_NAME parameter.

    This commit revers the change to handle the deployment file from
    the dcmanager, passing the responsability to the Deployment.

    Closes-Bug: 2036632

    Test Plan:

    PASS: Add a new subcloud and validate the content of
    deployment_config.yaml inside of subcloud. The value of
    OS_REGION_NAME parameter should be equal to the same parameter
    taken from environment variables.

    Change-Id: Ie50459930e968ab5b5c0940e71110b636df297a6
    Signed-off-by: Cristian Mondo <email address hidden>