title: spark.sql.crossJoin.enabled for Spark 2.x
body: <p>I am  using the 'preview' Google DataProc Image 1.1 with Spark 2.0.0. To complete one of my operations I have to complete a cartesian product. Since version 2.0.0 there has been a spark configuration parameter created (spark.sql.cross Join.enabled) that prohibits cartesian products and an  Exception is thrown. How can I set spark.sql.crossJoin.enabled=true, preferably by using an initialization action?
  <code>spark.sql.crossJoin.enabled=true</code></p>