[ML] Remove unused imports in GetDatafeedsStatsAction
Original commit: elastic/x-pack-elasticsearch@83abaae58e7a0fa04401eb0375e439092d9b4862
@@ -42,9 +42,7 @@ import org.elasticsearch.xpack.persistent.PersistentTasksCustomMetaData;
import org.elasticsearch.xpack.persistent.PersistentTasksCustomMetaData.PersistentTask;
import java.io.IOException;
-import java.util.ArrayList;
import java.util.Collections;
-import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
