Error to verify persistent_size value type

[Shrikumar Sharma]

Brief Description
When we try to verify the data type of persistent_size, the code throws an
error and the procedure is unable to progress any further.

Severity
Critical

Steps to Reproduce
Edit install-values file, add "persistent_size" parameter to any value
update subcloud install values

Expected Behavior
The value of persistent_size should be updated

Actual Behavior
It fails to update the value and throws an error, preventing the procedure
from progressing further.
Note: it also happens when you add a subcloud

Reproducibility
100% reproducible

System Configuration
DC

Branch/Pull Time/Commit
load: 22.02_2022-02-19_20-00-05
Feb. 21, 2022 master build

Last Pass
New test scenario.

Timestamp/Logs
 if not str(persistent_size).isnumeric():
AttributeError: 'str' object has no attribute 'isnumeric'
2022-02-22 15:33:42.807 131707 INFO eventlet.wsgi.server [req-5fb8d095-5c0e-4132-bce2-4973457ba67a 1857f140e3e34f4a929884f025f36cce - - default default] fd01:177::2 "PATCH /v1.0/subclouds/subcloud2 HTTP/1.1" status: 500 len: 139 time: 0.0731120

Alarms{}
None

Test Activity
Integration Test

Workaround
None

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/distcloud/+/830547

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/distcloud/+/830547
Committed: https://opendev.org/starlingx/distcloud/commit/a84005bcaba19d3437dc3a853f1d8860f5d7a29a
Submitter: "Zuul (22348)"
Branch: master

commit a84005bcaba19d3437dc3a853f1d8860f5d7a29a
Author: Shrikumar Sharma <email address hidden>
Date: Tue Feb 22 22:18:28 2022 -0500

    Error in verification of persistent_size value type

    This fixes an issue in the verification of the persistent_size
    value type.

    Test Plan:
    PASS: Verify graceful failure if persistent_value is not an
          integer

    PASS: Verify that the subcloud is configured with platform_backup
          size equal to persistent_size

    Closes-Bug: 1961860
    Change-Id: Ia758f8a07c752ab983728f0a36d8d6201bef0320
    Signed-off-by: Shrikumar Sharma <email address hidden>