RFR: JDK-8327474 Review use of java.io.tmpdir in jdk tests

[Bill Huang]

This task addresses an essential aspect of our testing infrastructure: the proper handling and cleanup of temporary files and socket files created during test execution. The motivation behind these changes is to prevent the accumulation of unnecessary files in the default temporary directory, which can affect the system's storage and potentially influence subsequent test runs.

Our review identified that several tests create temporary files or socket files without ensuring their removal post-execution. 
- Direct calls to java.io.File.createTempFile and java.nio.file.Files.createTempFile without adequate cleanup.
- Tests using NIO socket channels with StandardProtocolFamily.UNIX, not explicitly removing socket files post-use.

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Commit messages:
 - Clean up temporary files after tests complete.

Changes: https://git.openjdk.org/jdk/pull/18352/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18352&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8327474
  Stats: 42 lines in 11 files changed: 20 ins; 1 del; 21 mod
  Patch: https://git.openjdk.org/jdk/pull/18352.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18352/head:pull/18352

PR: https://git.openjdk.org/jdk/pull/18352