Added comment to authSecret field in manifest

[meggm]

Description

Added the required comments for the authSecret field in the manifest file.

GitHub Issues

List the GitHub issues impacted by this PR:

GitHub Issue #
dell/csm#583

Checklist:

• I have performed a self-review of my own code to ensure there are no formatting, vetting, linting, or security issues
• I have verified that new and existing unit tests pass locally with my changes
• I have not allowed coverage numbers to degenerate
• I have maintained at least 90% code coverage
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have maintained backward compatibility

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Please also list any relevant details for your test configuration

• Test A
• Deployed the PowerStore driver via CSM-operator after the comment has been added.