Update Public API for OP Splunk HEC destination indexed_fields (#3689)

Co-authored-by: ci.datadog-api-spec <packages@datadoghq.com>

Author: api-clients-generation-pipeline[bot]

.generator/schemas/v2/openapi.yaml

@@ -46462,6 +46462,15 @@ components:
           description: Optional name of the Splunk index where logs are written.
           example: main
           type: string
+        indexed_fields:
+          description: List of log field names to send as indexed fields to Splunk
+            HEC. Available only when `encoding` is `json`.
+          example:
+          - service
+          - host
+          items:
+            type: string
+          type: array
         inputs:
           description: A list of component IDs whose output is used as the `input`
             for this component.

services/observability_pipelines/src/v2/models/ObservabilityPipelineSplunkHecDestination.ts

@@ -35,6 +35,10 @@ export class ObservabilityPipelineSplunkHecDestination {
    * Optional name of the Splunk index where logs are written.
    */
   "index"?: string;
+  /**
+   * List of log field names to send as indexed fields to Splunk HEC. Available only when `encoding` is `json`.
+   */
+  "indexedFields"?: Array<string>;
   /**
    * A list of component IDs whose output is used as the `input` for this component.
    */
@@ -91,6 +95,10 @@ export class ObservabilityPipelineSplunkHecDestination {
       baseName: "index",
       type: "string",
     },
+    indexedFields: {
+      baseName: "indexed_fields",
+      type: "Array<string>",
+    },
     inputs: {
       baseName: "inputs",
       type: "Array<string>",