title: Cloud sql database export import issue
body: <p>When exporting an sql database from an instance (2nd gen) and importing it on another sql instance, I get the following error: 
  ERROR 1839 (HY000) at line 24:</p>
  
  <pre><code>@@GLOBAL.GTID_PURGED can only be set when @@GLOBAL.GTID_MODE = ON.
  </code></pre>
  
  <p>According to <a href="https://superuser.com/questions/906843/import-mysql-data-failed-with-error-1839">https://superuser.com/questions/906843/import-mysql-data-failed-with-error-1839</a> this could be solved by making an sql dump with </p>
  
  <pre><code>--set-gtid-purged=OFF
  </code></pre>
  
  <p>But the gcloud sql instances export command does not support this. Is there another way to solve this issue?</p>