Should not allow negative count value for unique_last_password_count

[Alexandre Horst]

Brief Description
-----------------
From the cli, the new command to add unique_last_password_count to be negative numbers

$ system service-parameter-add identity security_compliance unique_last_password_count

Severity
--------
<Minor: System/Feature is usable with minor issue>

Steps to Reproduce
------------------
Add or modify the security compliance setting for the last password count

eg.

$ system service-parameter-add identity security_compliance unique_last_password_count=-3

Expected Behavior
-----------------
Expect validation on negative value should be rejected

Actual Behavior
-----------------
The negative value was allowed and accepted on apply

$ system service-parameter-add identity security_compliance unique_last_password_count=-3

$ system service-parameter-apply identity
Applying identity service parameters

Reproducibility
---------------
yes

System Configuration
--------------------
simpex (any)

Branch/Pull Time/Commit
-----------------
2021-11-08_00-00-07"

Last Pass
---------
N/A

Timestamp/Logs
--------------
Provide a snippet of logs if available and the timestamp when issue was seen.

Please indicate the unique identifier in the logs to highlight the problem

Attach the logs for debugging

Alarms
------
Please indicate if there are any alarms observed.

If there are any alarms please list them here

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

Workaround
----------
Describe workaround if available

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/config/+/817937

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/config/+/817937
Committed: https://opendev.org/starlingx/config/commit/e21a2cc327bb2deb1bfb66e5e46fadc715aa7c37
Submitter: "Zuul (22348)"
Branch: master

commit e21a2cc327bb2deb1bfb66e5e46fadc715aa7c37
Author: Alexandre Horst <email address hidden>
Date: Mon Nov 15 09:34:16 2021 -0300

    Add a new validation function

    The service parameter are accepting negative values for the
    unique last password counter. The fix changes the validation for
    positive integer or zero.

    Test Plan:

    PASS: Verify parameter in command 'system service-parameter-add
          identity security_compliance unique_last_password_count' are not
          accepting negative values.

    Closes-Bug: 1950937
    Change-Id: I54866078622308057c350d32adb05c573cd12cdc
    Signed-off-by: Alexandre Horst <email address hidden>