Update enable-network-protection.md

[YongRhee-MSFT]

Updated the Windows Server info, where Windows Server 2019 was missing in the PoSh cmdlet. And added that for the downlevel servers, it requires the unified agent for MDE.

[learn-build-service-prod]

Learn Build status updates of commit 9740a2d:

💡 Validation status: suggestions

File	Status	Preview URL	Details
defender-endpoint/enable-network-protection.md	💡Suggestion		Details

defender-endpoint/enable-network-protection.md

• Line 88, Column 63: [Suggestion: docs-link-absolute - See documentation] Absolute link 'https://learn.microsoft.com/defender-endpoint/enable-network-protection' will be broken in isolated environments. Replace with a relative link.

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[learn-build-service-prod]

Learn Build status updates of commit 4df40ba:

✅ Validation status: passed

File	Status	Preview URL	Details
defender-endpoint/enable-network-protection.md	✅Succeeded

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• Post your question in the Learn support channel

[learn-build-service-prod]

Learn Build status updates of commit 52ddd14:

✅ Validation status: passed

File	Status	Preview URL	Details
defender-endpoint/enable-network-protection.md	✅Succeeded

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel