[jdk21u-dev] RFR: 8320349: Simplify FileChooserSymLinkTest.java by using single-window testUI

[Goetz Lindenmaier]

I backport this for parity with 21.0.4-oracle.

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Commit messages:
 - Backport b1cb37432a4b4a10ba68f468e4d988f2a935f198

Changes: https://git.openjdk.org/jdk21u-dev/pull/486/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=486&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8320349
  Stats: 4 lines in 1 file changed: 0 ins; 2 del; 2 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/486.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/486/head:pull/486

PR: https://git.openjdk.org/jdk21u-dev/pull/486