Fix indices.delete_alias response (#2951) (#4971)

* Fix indices.delete_api response

* specific ack response for indices delete alias

---------

Co-authored-by: Laura Trotta <[email protected]>
(cherry picked from commit 4926284)

# Conflicts:
#	specification/indices/delete_alias/IndicesDeleteAliasResponse.ts

Author: pquentin

output/openapi/elasticsearch-openapi.json

@@ -20,5 +20,9 @@
 import { AcknowledgedResponseBase } from '@_types/Base'
 
 export class Response {
-  body: AcknowledgedResponseBase
+  body: IndicesAliasesResponseBody
+}
+
+export class IndicesAliasesResponseBody extends AcknowledgedResponseBase {
+  errors?: boolean
 }