MINOR: Cleanup JMH-Benchmarks Module

[sjhajharia]

Now that Kafka supports Java 17, this PR makes some changes in jmh-benchmarks module. The changes mostly include:

• Collections.emptyList(), Collections.singletonList() and Arrays.asList() are replaced with List.of()
• Collections.emptyMap() and Collections.singletonMap() are replaced with Map.of()
• Collections.singleton() is replaced with Set.of()

[Yunyung]

Thanks for the PR. Could you also do this cleanup? Collections.unmodifiableMap -> Map.copyOf

[sjhajharia]

Thanks @Yunyung for the review. I have addressed the comment. PTAL when possible!

[m1a2st]

Please resolve the conflict, thanks

[sjhajharia]

Hey @m1a2st I have updated the PR

[sjhajharia]

cc: @frankvicky

[sjhajharia]

Hey @frankvicky If you can pls have a look at this PR too.

[sjhajharia]

Gentle reminder @frankvicky @chia7712

[sjhajharia]

Gentle reminder @chia7712 @frankvicky

[sjhajharia]

Hey @chia7712 Gentle reminder!