Fixed the tag issue

Author: Prekshith-Microsoft

content-gen/infra/main.bicep

@@ -275,13 +275,15 @@ resource avmTelemetry 'Microsoft.Resources/deployments@2024-03-01' = if (enableT
 resource resourceGroupTags 'Microsoft.Resources/tags@2021-04-01' = {
   name: 'default'
   properties: {
-    tags: {
-      ...resourceGroup().tags
-      ... tags
-      TemplateName: 'ContentGen'
-      Type: enablePrivateNetworking ? 'WAF' : 'Non-WAF'
-      CreatedBy: createdBy
-    }
+    tags: union(
+      resourceGroup().tags ?? {},
+      tags,
+      {
+        TemplateName: 'ContentGen'
+        Type: enablePrivateNetworking ? 'WAF' : 'Non-WAF'
+        CreatedBy: createdBy
+      }
+    )
   }
 }