Fixing inference service test deprecation warning in search tests (el…

…astic#204386)

Adds a `model_id` property to the model config and renames the service
to `elasticsearch`, as `elser` has been deprecated.
This should avoid triggering API deprecation warning.

x-pack/test_serverless/functional/test_suites/search/inference_management.ts

@@ -26,10 +26,11 @@ export default function ({ getPageObjects, getService }: FtrProviderContext) {
     const endpoint = 'endpoint-1';
     const taskType = 'sparse_embedding';
     const modelConfig = {
-      service: 'elser',
+      service: 'elasticsearch',
       service_settings: {
         num_allocations: 1,
         num_threads: 1,
+        model_id: '.elser_model_2',
       },
     };