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[bot]]

Learn Build status updates of commit f0613f5:

:white_check_mark: Validation status: passed

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

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