[jdk8u-dev] RFR: 8335845: [8u] Fix hotspot/test/runtime/containers tests for jdks with symlinked conf dir

[SendaoYan]

Hi all
Fix the testcase bug, which if the tested jdk directory is symlinked, symlinks are followed when copying tested jdk.
Only change the testcase lib file, the risk is low.
This is similar to [JDK-8309138](https://bugs.openjdk.org/browse/JDK-8309138), but in jdk8u-dev repository, there is a separated DockerTestUtils.java in hotspot/test directory.

Additional testing:

- [x] hotspot/test/runtime/containers/docker

[docker-tests.log](https://github.com/user-attachments/files/16124421/docker-tests.log)

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Commit messages:
 - 8335845: [8u] Fix hotspot/test/runtime/containers tests for jdks with symlinked conf dir

Changes: https://git.openjdk.org/jdk8u-dev/pull/539/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=539&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8335845
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/539.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/539/head:pull/539

PR: https://git.openjdk.org/jdk8u-dev/pull/539