helm-chart-attributes do not survive application-update

[Fabricio Henrique Ramos]

Brief Description
-----------------
application-update when helm-charts are disabled on the from_app does not preserve this helm-chart-attributes on the to_app.

It will probably occur with any application. Likely a day 1 issue.

Severity
--------

Minor: System/Feature is usable with minor issue

Steps to Reproduce
------------------
Use system helm-chart-attribute-modify to disable a chart group of an application

apply the application

application-update to a new version of the application (a new tarball with updated version is enough)

The previously disabled chart-groups are now launched.

Expected Behavior
------------------
Disabled helm charts should stay disabled after application-update

Actual Behavior
----------------
Disabled helm charts get created after application-update even if they were disabled.

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

System Configuration
--------------------
Any

Branch/Pull Time/Commit
-----------------------
SW_VERSION="22.02"
BUILD_TARGET="Host Installer"
BUILD_TYPE="Formal"
BUILD_ID="2022-03-03_20-00-07"
SRC_BUILD_ID="1192"

Last Pass
---------
n/a

Timestamp/Logs
--------------
n/a
Test Activity
-------------
Developer Testing

Workaround
----------
After application-update, disabled the helm charts again and re-apply the application.

[Ghada Khalil (gkhalil)]

Fixed By: https://review.opendev.org/c/starlingx/config/+/865327

Note: The LP was not updated properly since the Closes-Bug in the commit msg didn't have the proper format.

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/config/+/877698

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/config/+/877698
Committed: https://opendev.org/starlingx/config/commit/09661f773626c123af29a231384777de0388f195
Submitter: "Zuul (22348)"
Branch: master

commit 09661f773626c123af29a231384777de0388f195
Author: Dan Voiculeasa <email address hidden>
Date: Thu Mar 16 18:32:12 2023 +0200

    AppFwk: Add docstring for maintain_attributes

    A docstring was missed when the functionality was implemented [1].
    Add the missing docstring.

    Skip tests because there is no functional impact.

    [1]: https://review.opendev.org/c/starlingx/config/+/865327
    Related-Bug: 1998499
    Signed-off-by: Dan Voiculeasa <email address hidden>
    Change-Id: Ia1b5d281ebe67c4f1605cf2d645f896bb1e2b6e6