[Partial Backport 8.15] Java issue batch 8 (#2959)

Author: l-trotta

output/openapi/elasticsearch-openapi.json

@@ -89,7 +89,8 @@ export class IndicesResponseBase extends AcknowledgedResponseBase {
 }
 
 export class ShardsOperationResponseBase {
-  _shards: ShardStatistics
+  // _shards is always returned, but not when wait_for_completion is false in the request
+  _shards?: ShardStatistics
 }
 
 export class CustomResponseBuilderBase {}

output/openapi/elasticsearch-serverless-openapi.json

@@ -30,7 +30,7 @@ export interface Request extends RequestBase {
     index: IndexName
   }
   body: {
-    current_step?: StepKey
-    next_step?: StepKey
+    current_step: StepKey
+    next_step: StepKey
   }
 }

output/schema/schema-serverless.json

@@ -18,7 +18,8 @@
  */
 
 export class StepKey {
-  action: string
-  name: string
+  // action and name are optional in case they are used in next_step
+  action?: string
+  name?: string
   phase: string
 }

output/schema/schema.json

@@ -143,4 +143,5 @@ export class DataStreamIndex {
 
 export class DataStreamVisibility {
   hidden?: boolean
+  allow_custom_routing?: boolean
 }