Persistent size change does not take effect over simplex upgrade

[Tee Ngo]

Brief Description
-----------------
The /opt/platform-backup size remains to be 30G (default size) after upgrade despite the fact the persistent_size was increased beforehand.

Severity
--------
Major

Steps to Reproduce
------------------
1. In a DC system where the system controller has been ugraded
2. Increase the persistent size of a simplex subcloud using dcmanager subcloud
   update --install-values command
3. Upgrade the subcloud

Expected Behavior
------------------
The /opt/platform-backup has the new size after upgrade

Actual Behavior
----------------
Subcloud was upgraded successfully but /opt/platform-backup was still at default size.
The commit: https://review.opendev.org/c/starlingx/distcloud/+/826149 missed upgrade scenario.

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

System Configuration
--------------------
Distributed Cloud

Branch/Pull Time/Commit
-----------------------
2022-02-21 master build

Last Pass
---------
first time testing https://storyboard.openstack.org/#!/story/2009799 (task 44356) over upgrade

Timestamp/Logs
--------------
N/A (subcloud upgrade was successful but user's config change was not respected)

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

Workaround
----------
None

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/distcloud/+/831013

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/distcloud/+/831013
Committed: https://opendev.org/starlingx/distcloud/commit/765cd0b5c06f1efcd2b9aa3e1db3ee9e3ca08273
Submitter: "Zuul (22348)"
Branch: master

commit 765cd0b5c06f1efcd2b9aa3e1db3ee9e3ca08273
Author: Tee Ngo <email address hidden>
Date: Fri Feb 25 11:13:20 2022 -0500

    Provide persistent_size value over simplex upgrade

    The previous commit to support persistent_size in subcloud
    install values (74bf7032123207503086fa7880a0fd74eaf2849c) ommitted
    the upgrade path. This commit fixes it.

    Test Plan:
      - Increase subcloud persistent size (e.g. 40000) using
        dcmanager subcloud update --install-values command.
      - Perform orchestrated subcloud upgrade.
      - Verify that the subcloud has new persistent size as configured
        after the upgrade.

    Closes-Bug: 1962326
    Change-Id: I52eb897a8b0e7dec9f4e1ed872b96406bfc04173
    Signed-off-by: Tee Ngo <email address hidden>