Update Get-ADServiceAccount.md

[HerbertMauerer]

PR Summary

PR Checklist

• Descriptive Title: Add cross-domain example and remove mention of LDS.
• Summary: add cross-domain example, remove LDS in -Partition parameter as GMSAs don't exist in LDS. consistent use of quotes in examples.
• Contributor's Guide: I have read the [contributors guide][yes].
• Style: This PR adheres to the [style guide][yes].

[learn-build-service-prod]

Learn Build status updates of commit f0613f5:

✅ Validation status: passed

File	Status	Preview URL	Details
docset/winserver2022-ps/activedirectory/Get-ADServiceAccount.md	✅Succeeded	View (WindowsServer2022-ps)

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