Update EIS sparse embedding max batch size to 16

Author: jaybcee

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elastic/ElasticInferenceService.java

@@ -91,7 +91,7 @@ public class ElasticInferenceService extends SenderService {
     public static final String NAME = "elastic";
     public static final String ELASTIC_INFERENCE_SERVICE_IDENTIFIER = "Elastic Inference Service";
     public static final Integer DENSE_TEXT_EMBEDDINGS_DIMENSIONS = 1024;
-    public static final Integer SPARSE_TEXT_EMBEDDING_MAX_BATCH_SIZE = 512;
+    public static final Integer SPARSE_TEXT_EMBEDDING_MAX_BATCH_SIZE = 16;
 
     private static final EnumSet<TaskType> IMPLEMENTED_TASK_TYPES = EnumSet.of(
         TaskType.SPARSE_EMBEDDING,