[SPARK-19444][ML][DOCUMENTATION] Fix imports not being present in documentation

## What changes were proposed in this pull request?

SPARK-19444 imports not being present in documentation

## How was this patch tested?

Manual

## Disclaimer

Contribution is original work and I license the work to the project under the project’s open source license

Author: Aseem Bansal <anshbansal@users.noreply.github.com>

Closes #16789 from anshbansal/patch-1.

(cherry picked from commit aee2bd2c)
Signed-off-by: Sean Owen <sowen@cloudera.com>

examples/src/main/java/org/apache/spark/examples/ml/JavaTokenizerExample.java

@@ -35,13 +35,11 @@ import org.apache.spark.sql.types.DataTypes;
 import org.apache.spark.sql.types.Metadata;
 import org.apache.spark.sql.types.StructField;
 import org.apache.spark.sql.types.StructType;
-// $example off$
 
-// $example on:untyped_ops$
 // col("...") is preferable to df.col("...")
 import static org.apache.spark.sql.functions.callUDF;
 import static org.apache.spark.sql.functions.col;
-// $example off:untyped_ops$
+// $example off
 
 public class JavaTokenizerExample {
   public static void main(String[] args) {