Fix passing credential to the SyncGalleryToAzArtifacts.psm1 script (#8808)

Fix the parameter names and AzDevOps pipeline variable names.

## PR Context  

Variable names were out of sync with the definition on AzDevOps.

tools/releaseBuild/azureDevOps/AzArtifactFeed/PSGalleryToAzArtifacts.yml

@@ -15,7 +15,7 @@ steps:
 
   - powershell: |
       Import-Module -Force "$(Build.SourcesDirectory)/tools/releaseBuild/azureDevOps/AzArtifactFeed/SyncGalleryToAzArtifacts.psm1"
-      SyncGalleryToAzArtifacts -AzDevOpsPAT $(AzDevOpsPAT) -Destination $(Build.ArtifactStagingDirectory)
+      SyncGalleryToAzArtifacts -AzDevOpsFeedUserName $(AzDevOpsFeedUserName) -AzDevOpsPAT $(AzDevOpsFeedPAT) -Destination $(Build.ArtifactStagingDirectory)
     displayName: Download packages from PSGallery that need to be updated
     condition: succeededOrFailed()
 

tools/releaseBuild/azureDevOps/AzArtifactFeed/SyncGalleryToAzArtifacts.psm1

@@ -14,6 +14,7 @@ Path to the folder where the packages should be stored for uploading to Azure De
 #>
 function SyncGalleryToAzArtifacts {
     param(
+        [Parameter(Mandatory = $true)] [string] $AzDevOpsFeedUserName,
         [Parameter(Mandatory = $true)] [string] $AzDevOpsPAT,
         [Parameter(Mandatory = $true)] [string] $Destination
     )
@@ -28,7 +29,7 @@ function SyncGalleryToAzArtifacts {
     $galleryUrl = 'https://www.powershellgallery.com/api/v2/'
     $azArtifactsUrl = 'https://mscodehub.pkgs.visualstudio.com/_packaging/pscore-release/nuget/v2'
 
-    $azDevOpsCreds = [pscredential]::new($env:AzDevOpsUserName, (ConvertTo-SecureString -String $AzDevOpsPAT -AsPlainText -Force))
+    $azDevOpsCreds = [pscredential]::new($AzDevOpsFeedUserName, (ConvertTo-SecureString -String $AzDevOpsPAT -AsPlainText -Force))
 
     foreach ($package in $packages) {
         try {