Add warning for Defender AV settings replacement

[rakena]

Added a warning about replacing existing Defender AV settings when deploying or updating the extension.
This is based on customer escalation (strategic customer Mediterranean Shipping) and requested by CXP ACE team.

[prmerger-automator]

@rakena : Thanks for your contribution! The author(s) and reviewer(s) have been notified to review your proposed change.

[learn-build-service-prod]

Learn Build status updates of commit 3e58a63:

✅ Validation status: passed

File	Status	Preview URL	Details
articles/security/fundamentals/antimalware-code-samples.md	✅Succeeded

For more details, please refer to the build report.

[v-regandowner]

Suggested change

	> Before executing this code sample, you must uncomment the variables and provide appropriate values.<br>
	> Before executing this code sample, you must uncomment the variables and provide appropriate values.

[v-regandowner]

Suggested change

	> WARNING: Deploying or updating this extension will replace existing Defender AV settings, including exclusions.
	> [!WARNING]
	> Deploying or updating this extension will replace existing Defender AV settings, including exclusions.

[v-regandowner]

@msmbaldwin - Can you review the proposed changes?

IMPORTANT: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged"
@MicrosoftDocs/public-repo-pr-review-team

[v-dirichards]

@msmbaldwin

Can you review this old PR and determine whether it needs to be closed or merged?

@MicrosoftDocs/public-repo-pr-review-team

[Copilot]

Pull Request Overview

This PR adds a warning to inform users that deploying or updating the Microsoft Antimalware extension will replace existing Defender AV settings, including exclusions. This change addresses feedback from a strategic customer escalation.

• Added a warning message about replacement of existing Defender AV settings

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[Copilot]

[nitpick] The <br> HTML tag is used inconsistently with the Markdown format. Consider using a blank line with > to create a line break within the NOTE block, which is more idiomatic for Markdown blockquotes.

Suggested change

	> Before executing this code sample, you must uncomment the variables and provide appropriate values.<br>
	> Before executing this code sample, you must uncomment the variables and provide appropriate values.
	>