Make smoke tester script work on main branch (java 17)

The smoke tester script has been obsoleted on main after upgrading to Java 17. To enable nightly smoke tests on Jenkins for main, its target java version should be bumped to 17.

In addition to bump the java version, it looks it should be refactored not to hard-code target java version. I feel it'd be better to make it coordinate with the Gradle distribution task.