RFR: 8349121: SSLParameters.setApplicationProtocols() ALPN example could be clarified.

[Bradford Wetmore]

Update and clarify the sample code.

Docs only, no additional testing other than verifying javadoc is correctly output.

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Commit messages:
 - 8349121: SSLParameters.setApplicationProtocols() ALPN example could be clarified

Changes: https://git.openjdk.org/jdk/pull/23379/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23379&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8349121
  Stats: 16 lines in 1 file changed: 9 ins; 1 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/23379.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23379/head:pull/23379

PR: https://git.openjdk.org/jdk/pull/23379