change deprecation warning, enclose some more parts with feature toggle

third_party/terraform/resources/resource_compute_network_peering.go.erb

@@ -46,7 +46,7 @@ func resourceComputeNetworkPeering() *schema.Resource {
 			"auto_create_routes": {
 				Type:             schema.TypeBool,
 				Optional:         true,
-				Deprecated:       "auto_create_routes is deprecated use exchange_subnet_routes instead",
+				Deprecated:       "auto_create_routes has been deprecated because it's redundant and not user-configurable. It can safely be removed from your config",
 				ForceNew:         true,
 				Default:          true,
 			},
@@ -184,8 +184,10 @@ func findPeeringFromNetwork(network *computeBeta.Network, peeringName string) *c
 }
 func expandNetworkPeering(d *schema.ResourceData) *computeBeta.NetworkPeering {
 	return &computeBeta.NetworkPeering{
+		<% unless version == 'ga' -%>
 		ExportCustomRoutes:     d.Get("export_custom_routes").(bool),
 		ImportCustomRoutes:     d.Get("import_custom_routes").(bool),
+        <% end -%>
 		// auto_create_routes was replaced by exchange_subnet_routes in the network peering object
 		ExchangeSubnetRoutes:   true,
 		Name:					d.Get("name").(string),