Replaced Utils.join() with JDK API.

[samalapurapu]

Problem

Solution

Does this solution apply anywhere else?

• [ ] yes
• [ ] no

If yes, where?

Test Strategy

Testing done:

• [ ] Unit tests
• [ ] Integration tests
• [ ] System tests
• [ ] Manual tests

Release Plan

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[sappusaketh]

@samalapurapu or @vbalani002 can this be merged? This is blocking us from upgrading to kafka 3.8+