title: PySpark dataframe approxQuantile returns result as List
body: <p>I am using following function to get the percentiles from two columns "Apple" and "Oranges". However, i am getting the result back as a list. </p>
  
  <pre><code>df.approxQuantile(['Apple', 'Oranges'],[0.1, 0.25, 0.5, 0.75, 0.9, 0.95],0.1)
  </code></pre>
  
  <p>I want to get the result back as columns. Any suggestions :</p>
  
  <p>Desired Output :</p>
  
  <pre><code>+-------+--------------------+---------------------+
  |Percentile |               Apple|      Oranges    |
  +-------+--------------------+---------------------+
  |  10      |              50     |              502|
  |  25      |              12     |              431|
  |  50      |              1.15   |             5065|
  |  75      |              3224   |             1275|
  |  90      |              2234   |              100|
  +-------+--------------------+---------------------+
  </code></pre>