[jdk21u-dev] RFR: 8187759: Background not refreshed when painting over a transparent JFrame

[Amos Shi]

Backport of [JDK-8187759](https://bugs.openjdk.org/browse/JDK-8187759)

Testing
- Local: Not tested - the test `JFrameBackgroundRefreshTest.java` needs `os.family == "linux"`, while the local is MacOS
- Pipeline: 
- Testing Machine:

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Commit messages:
 - Backport 04d43c435d3ede519df169053dd9d724aa2312eb

Changes: https://git.openjdk.org/jdk21u-dev/pull/487/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=487&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8187759
  Stats: 219 lines in 2 files changed: 219 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/487.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/487/head:pull/487

PR: https://git.openjdk.org/jdk21u-dev/pull/487