Subcloud can be prestaged while backup create task is in progress

[Li Zhu]

Brief Description
-----------------
Subcloud can be prestaged while backup create task is in progress

Note:
When we prestage a subcloud that has a backup create operation also in progress, both tasks are completed successfully.
The only impact that I see in this scenario is that the ansible logs gets messed up with logs from two playbooks that are being executed in parallel.

Severity
--------
Minor

Steps to Reproduce
------------------
deploy subcloud
manage subcloud
run backup create command for the subcloud and in parallel run subcloud prestage for the same subcloud

Expected Behavior
------------------
command for subcloud prestage should be rejected

Actual Behavior
----------------
command for subcloud prestage should be rejected

Reproducibility
---------------
100% reproducible

System Configuration
--------------------
DC

Branch/Pull Time/Commit
-----------------------
Apr 15, 2023 master load

Last Pass
---------

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

Test Activity
-------------
Feature Testing

Workaround
----------
No workaround

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/distcloud/+/892042

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/distcloud/+/892042
Committed: https://opendev.org/starlingx/distcloud/commit/ccf55d7263196d880d435ba5a7462f8b7fc019d7
Submitter: "Zuul (22348)"
Branch: master

commit ccf55d7263196d880d435ba5a7462f8b7fc019d7
Author: Li Zhu <email address hidden>
Date: Fri Aug 18 17:46:14 2023 -0400

    Disallow subcloud prestage while backup is in progress

    Backup and prestage operations are not allowed to be running in parallel
    on a subcloud. This commit adds a check for backup status to prestage
    validation.

    Test Plan:
    PASS: The prestage operation is rejected while backup in progress
          on a subcloud.
    PASS: Successfully run prestage while no backup in progress on a
          subcloud.

    Closes-Bug: 2031947

    Change-Id: If91b21f12f6865f9f252a3b9538247194c19e18a
    Signed-off-by: lzhu1 <email address hidden>