[HUDI-3337] Fixing Parquet Column Range metadata extraction (#4705)

- Parquet Column Range metadata extraction utility was simplistically assuming that Decimal types are only represented by INT32, while they representation varies depending on precision.

- More details could be found here:
https://github.com/apache/parquet-format/blob/master/LogicalTypes.md#DECIMAL

hudi-client/hudi-spark-client/src/main/java/org/apache/hudi/index/columnstats/ColumnStatsIndexHelper.java

@@ -29,7 +29,6 @@ import org.apache.hudi.common.util.collection.Pair;
 import org.apache.hudi.exception.HoodieException;
 import org.apache.log4j.LogManager;
 import org.apache.log4j.Logger;
-import org.apache.parquet.io.api.Binary;
 import org.apache.spark.SparkContext;
 import org.apache.spark.api.java.JavaRDD;
 import org.apache.spark.api.java.JavaSparkContext;
@@ -62,6 +61,7 @@ import scala.collection.JavaConversions;
 import javax.annotation.Nonnull;
 import java.io.IOException;
 import java.math.BigDecimal;
+import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -422,9 +422,8 @@ public class ColumnStatsIndexHelper {
       );
     } else if (colType instanceof StringType) {
       return Pair.of(
-          new String(((Binary) colMetadata.getMinValue()).getBytes()),
-          new String(((Binary) colMetadata.getMaxValue()).getBytes())
-      );
+          colMetadata.getMinValue().toString(),
+          colMetadata.getMaxValue().toString());
     } else if (colType instanceof DecimalType) {
       return Pair.of(
           new BigDecimal(colMetadata.getMinValue().toString()),
@@ -447,8 +446,8 @@ public class ColumnStatsIndexHelper {
           new Float(colMetadata.getMaxValue().toString()));
     } else if (colType instanceof BinaryType) {
       return Pair.of(
-          ((Binary) colMetadata.getMinValue()).getBytes(),
-          ((Binary) colMetadata.getMaxValue()).getBytes());
+          ((ByteBuffer) colMetadata.getMinValue()).array(),
+          ((ByteBuffer) colMetadata.getMaxValue()).array());
     } else if (colType instanceof BooleanType) {
       return Pair.of(
           Boolean.valueOf(colMetadata.getMinValue().toString()),