Index settings lifecycle name should be optional, not ILM policy name (#2498)

See elastic/elasticsearch-java#456

(cherry picked from commit c2b68f5)

Author: JoshMock

specification/ilm/put_lifecycle/PutLifecycleRequest.ts

@@ -35,7 +35,7 @@ export interface Request extends RequestBase {
      * Identifier for the policy.
      * @codegen_name name
      */
-    policy?: Name
+    policy: Name
   }
   query_parameters: {
     /**

specification/indices/_types/IndexSettings.ts

@@ -275,7 +275,7 @@ export class IndexSettingsLifecycle {
   /**
    * The name of the policy to use to manage the index. For information about how Elasticsearch applies policy changes, see Policy updates.
    */
-  name: Name
+  name?: Name
   /**
    * Indicates whether or not the index has been rolled over. Automatically set to true when ILM completes the rollover action.
    * You can explicitly set it to skip rollover.