Minor hygiene, Removed Redundant inheritance

Close #9427

src/main/java/org/elasticsearch/index/merge/scheduler/MergeSchedulerProvider.java

@@ -37,7 +37,7 @@ import java.util.concurrent.CopyOnWriteArrayList;
 /**
  *
  */
-public abstract class MergeSchedulerProvider extends AbstractIndexShardComponent implements IndexShardComponent, Closeable {
+public abstract class MergeSchedulerProvider extends AbstractIndexShardComponent implements Closeable {
 
     public static interface FailureListener {
         void onFailedMerge(MergePolicy.MergeException e);

src/main/java/org/elasticsearch/index/shard/IndexShard.java

@@ -117,7 +117,7 @@ import static org.elasticsearch.index.mapper.SourceToParse.source;
 /**
  *
  */
-public class IndexShard extends AbstractIndexShardComponent implements IndexShardComponent {
+public class IndexShard extends AbstractIndexShardComponent {
 
     private final ThreadPool threadPool;
     private final IndexSettingsService indexSettingsService;