RFR: 8372118: Test tools/jpackage/macosx/DmgContentTest.java failed

[Alexey Semenyuk]

Don't follow symlinks when copying the app image directory tree into the blank .dmg file.

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Commit messages:
 - 8372118: Test tools/jpackage/macosx/DmgContentTest.java failed

Changes: https://git.openjdk.org/jdk/pull/28403/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28403&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8372118
  Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/28403.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28403/head:pull/28403

PR: https://git.openjdk.org/jdk/pull/28403