export com.sun.management.internal when running Druid under JRE11 and JRE17

[FrankChen021]

Fixes #12312 which was reported half a year ago.

This PR has:

• been self-reviewed.
  • using the concurrency checklist (Remove this item if the PR doesn't have any relation to concurrency.)
• added documentation for new or modified features or behaviors.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.

[gianm]

Couple questions:

• Is this still needed after the changes to JvmMonitor in Use MXBeans to get GC metrics #12476 #12481?
• Is it --add-exports or --add-opens that we need?

[FrankChen021]

• Is this still needed after the changes to JvmMonitor in Use MXBeans to get GC metrics #12476 #12481?

Yes, we need it. The AllocationMetricCollector differs from the JvmMonitor that we changed before, and I have not found a management API to replace it.

• Is it --add-exports or --add-opens that we need?

Basically, add-opens can be seen as a super set of add-exports. The former one allows us to access non-public methods via reflection while the latter one allows us to access public methods only. Use add-opens makes the things simpler.

[gianm]

ty, sounds good to me!