Add statement to remind users to lock/unlock controller nodes after installing a ssl_ca

[Juanita-Balaraj]

Brief Description
-----------------
Add statement to remind users to lock/unlock controller nodes after installing a ssl_ca.

Severity
--------
Provide the severity of the defect.
<Minor: System/Feature is usable with minor issue>

Steps to Reproduce
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https://docs.starlingx.io/security/kubernetes/configure-oidc-auth-applications.html
Note: it is necessary to ensure the system trusts the CA.  The gist of the text can be copied from section 1. b. Prerequisites "If a signing CA  is not a well-known trusted CA, you must ensure the system trusts the CA by specifying it either during the bootstrap phase of system installation, by specifying ssl_ca_cert: <certificate_file> in the ansible bootstrap overrides localhost.yml file, or by using the system certificate-install -m ssl_ca <certificate_file> command."

And append the sentence "Also refer to https://docs.starlingx.io/security/kubernetes/add-a-trusted-ca.html for installing a root CA, which includes instruction to lock/unlock controller nodes when using 'system certificate-install' command.
This last sentence can also be appended to section 1. b. Prerequisites, after "or by using the system certificate-install -m ssl_ca dex-ca.pem command."
The document to be changed is in starlingx/docs (https://opendev.org/starlingx/docs.git):
doc/source/security/kubernetes/configure-oidc-auth-applications.rst

Expected Behavior
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Write down what was expected after taking the steps written above

Actual Behavior
----------------
State what is the actual behavior

Reproducibility
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<Reproducible/Intermittent/Seen once>
State if the issue is 100% reproducible, intermittent or seen once. If it is intermittent, state the frequency of occurrence

System Configuration
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<One node system, Two node system, Multi-node system, Dedicated storage, https, IPv4, IPv6 etc.>

Branch/Pull Time/Commit
-----------------------
Branch and the time when code was pulled or git commit or cengn load info

Last Pass
---------
Did this test scenario pass previously? If so, please indicate the load/pull time info of the last pass.
Use this section to also indicate if this is a new test scenario.

Timestamp/Logs
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Attach the logs for debugging (use attachments in Launchpad or for large collect files use: https://files.starlingx.kube.cengn.ca/)
Provide a snippet of logs here and the timestamp when issue was seen.
Please indicate the unique identifier in the logs to highlight the problem

Test Activity
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[Sanity, Feature Testing, Regression Testing, Developer Testing, Evaluation, Other - Please specify]

Workaround
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Describe workaround if available

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/docs/+/868146

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/docs/+/868146
Committed: https://opendev.org/starlingx/docs/commit/cfed9ee0dc21f2b0b27be235757344ca77046772
Submitter: "Zuul (22348)"
Branch: master

commit cfed9ee0dc21f2b0b27be235757344ca77046772
Author: Elaine Fonaro <email address hidden>
Date: Mon Dec 19 20:38:36 2022 -0300

    Add a note users to lock/unlock controller nodes after installing a ssl_ca

    - Added a note for lock/unlock controler node.
    - Added a reference for installing a root CA.

    Closes-bug: 1995145

    Signed-off-by: Elaine Fonaro <email address hidden>
    Change-Id: I293ecc19348308e60da7f5922d169c455b895576