[jdk21u-dev] RFR: 8328385: Convert java/awt/FileDialog/FileDialogReturnTest test to main

[Goetz Lindenmaier]

I backport this for parity with 21.0.9-oracle

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Commit messages:
 - Backport c7cf6020782525eb17ff3013195a81d711a4fce1

Changes: https://git.openjdk.org/jdk21u-dev/pull/2050/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=2050&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8328385
  Stats: 431 lines in 3 files changed: 142 ins; 289 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/2050.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/2050/head:pull/2050

PR: https://git.openjdk.org/jdk21u-dev/pull/2050