Clarify that app lifecycle type cannot be changed

Author: sethboyles

docs/v3/source/includes/resources/apps/_update.md.erb

@@ -39,7 +39,7 @@ Content-Type: application/json
 Name | Type | Description
 ---- | ---- | -----------
 **name** | _string_ | Name of the app
-**lifecycle** | [_lifecycle object_](#the-lifecycle-object) | Lifecycle to be used when updating the app; note: `data` is a required field in lifecycle if lifecycle is updated
+**lifecycle** | [_lifecycle object_](#the-lifecycle-object) | Lifecycle to be used when updating the app; note: `data` is a required field in lifecycle if lifecycle is updated. `type` may NOT be changed from its current value.
 **metadata.labels** | [_label object_](#labels) | Labels applied to the app
 **metadata.annotations**  | [_annotation object_](#annotations) | Annotations applied to the app