[LIVY-1017] Support Java 17, set up JDK 17 based tests

[gyogal]

What changes were proposed in this pull request?

Enable Livy to run with Java 17, set up unit test and integration test runs with JDK 17

How was this patch tested?

Unit and integration tests.

[ArnavBalyan]

Hi @gyogal, thanks for working on this, the change looks good to me. I was planning to take up the Java 8 deprecation next, so I just wanted to check if you’re planning to land this soon? looks like a test is still failing. Thanks!

[gyogal]

Thank you very much for the review, @ArnavBalyan ! The checks are currently failing because the test Docker image does not contain JDK 17 yet, it is this change that adds it. After the merge the tests should look fine (I will confirm this and fix it if that is not the case).

Java 8 deprecation would be a great addition, thanks for looking into it! I think anything that impacts compatibility (Python 2, Spark 2, JDK 8 and general cleanup removing old features) could be done in the release following the next one.

[ArnavBalyan]

Thanks so much! I'll wait for this PR to land JDK 17, and proceed with the Java 8 deprecation cleanup, let me check the Spark 2 and Python2, there is a PR for Py2 deprecation which should be feasible once Spark 2 is deprecated.