Fix the bug that RowIndex column type cannot be serialized (#11208)

Summary:
Pull Request resolved: #11208

I came across a bug when I tried to serialize a TableScanNode with special row index column.

### The isssue
`folly::dynamic HiveColumnHandle::serialize()` uses `columnTypeNames` to serialize the TableScanNode. However, RowIndex is missing in `columnTypeNames`. serialize method would raise a std::out_of_range error because of this.

### The fix
The fix is simple -- just add row index column to the map.

Reviewed By: Yuhta

Differential Revision: D64088125

fbshipit-source-id: 7832e7e2fb6d471f294ae8bb3ff33f87d26d5279

velox/connectors/hive/TableHandle.cpp

@@ -25,7 +25,7 @@ columnTypeNames() {
       {HiveColumnHandle::ColumnType::kPartitionKey, "PartitionKey"},
       {HiveColumnHandle::ColumnType::kRegular, "Regular"},
       {HiveColumnHandle::ColumnType::kSynthesized, "Synthesized"},
-  };
+      {HiveColumnHandle::ColumnType::kRowIndex, "RowIndex"}};
 }
 
 template <typename K, typename V>