fixing arg parameters for Get/Set-SdnVMNetwork cmdlets

[arudell]

Description

Summary of changes:

• Fix an issue where invalid parameters being passed to sub-function

Change type

• Bug fix (non-breaking change)
• Code style update (formatting, local variables)
• New Feature (non-breaking change that adds new functionality without impacting existing)
• Breaking change (fix or feature that may cause functionality impact)
• Other

Checklist:

• My code follows the style and contribution guidelines of this project.
• I have tested and validated my code changes.