fixes after code review

Author: arolshan

src/OperationalInsights/OperationalInsights/ChangeLog.md

@@ -18,8 +18,6 @@
         - Additional information about change #1
 -->
 ## Upcoming Release
-
-## Version 1.2.1
 * Enable **pergb2018** pricing tier in `New-AzureRmOperationalInsightsWorkspace` command
 
 ## Version 1.2.0

src/OperationalInsights/OperationalInsights/Workspaces/NewAzureOperationalInsightsWorkspaceCommand.cs

@@ -42,7 +42,7 @@ public class NewAzureOperationalInsightsWorkspaceCommand : OperationalInsightsBa
 
         [Parameter(Position = 3, Mandatory = false, ValueFromPipelineByPropertyName = true,
             HelpMessage = "The service tier of the workspace.")]
-        [ValidateSet("free", "standard", "premium", "pernode", "standalone", "pergb2018", IgnoreCase = true)]
+        [PSArgumentCompleter("free", "standard", "premium", "pernode", "standalone", "pergb2018")]
         public string Sku { get; set; }
 
         [Parameter(Position = 4, Mandatory = false, ValueFromPipelineByPropertyName = true,