[SPARK-23388][SQL] Support for Parquet Binary DecimalType in VectorizedColumnReader

## What changes were proposed in this pull request?

Re-add support for parquet binary DecimalType in VectorizedColumnReader

## How was this patch tested?

Existing test suite

Author: James Thompson <jamesthomp@users.noreply.github.com>

Closes #20580 from jamesthomp/jt/add-back-binary-decimal.

Author: jamesthomp

sql/core/src/main/java/org/apache/spark/sql/execution/datasources/parquet/VectorizedColumnReader.java

@@ -444,7 +444,8 @@ private void readBinaryBatch(int rowId, int num, WritableColumnVector column) {
     // This is where we implement support for the valid type conversions.
     // TODO: implement remaining type conversions
     VectorizedValuesReader data = (VectorizedValuesReader) dataColumn;
-    if (column.dataType() == DataTypes.StringType || column.dataType() == DataTypes.BinaryType) {
+    if (column.dataType() == DataTypes.StringType || column.dataType() == DataTypes.BinaryType
+            || DecimalType.isByteArrayDecimalType(column.dataType())) {
       defColumn.readBinarys(num, column, rowId, maxDefLevel, data);
     } else if (column.dataType() == DataTypes.TimestampType) {
       if (!shouldConvertTimestamps()) {