Change Required parameter from True to False

Author: venkatasaimaram7

src/Network/Network/help/Get-AzDdosCustomPolicy.md

@@ -79,7 +79,7 @@ Type: System.String
 Parameter Sets: (All)
 Aliases:
 
-Required: True
+Required: False
 Position: Named
 Default value: None
 Accept pipeline input: True (ByPropertyName)