Add changes based on feedback

Author: inv-jishnu

data-loader/cli/src/main/java/com/scalar/db/dataloader/cli/command/dataexport/ExportCommand.java

@@ -64,15 +64,18 @@ public Integer call() throws Exception {
       validatePositiveValue(spec.commandLine(), maxThreads, DataLoaderError.INVALID_MAX_THREADS);
 
       TransactionFactory transactionFactory = TransactionFactory.create(scalarDbPropertiesFilePath);
-      TableMetadataService metaDataService =
-          new TableMetadataService(transactionFactory.getTransactionAdmin());
+      TableMetadata tableMetadata;
+      try (com.scalar.db.api.DistributedTransactionAdmin admin =
+          transactionFactory.getTransactionAdmin()) {
+        TableMetadataService metaDataService = new TableMetadataService(admin);
+        tableMetadata = metaDataService.getTableMetadata(namespace, table);
+      }
+
       ScalarDbDao scalarDbDao = new ScalarDbDao();
 
       ExportManager exportManager =
           createExportManager(transactionFactory, scalarDbDao, outputFormat);
 
-      TableMetadata tableMetadata = metaDataService.getTableMetadata(namespace, table);
-
       Key partitionKey =
           partitionKeyValue != null ? getKeysFromList(partitionKeyValue, tableMetadata) : null;
       Key scanStartKey =