[jdk20] RFR: 8299077: [REDO] JDK-4512626 Non-editable JTextArea provides no visual indication of keyboard focus

[Alexander Zuev]

Slightly updated original fix - got rid of the extra flasher reset. Tests are fixed to be more stable and pass on the corresponding platforms.

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Commit messages:
 - 8299077: [REDO] JDK-4512626 Non-editable JTextArea provides no visual indication of keyboard focus

Changes: https://git.openjdk.org/jdk20/pull/68/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk20&pr=68&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8299077
  Stats: 230 lines in 4 files changed: 70 ins; 76 del; 84 mod
  Patch: https://git.openjdk.org/jdk20/pull/68.diff
  Fetch: git fetch https://git.openjdk.org/jdk20 pull/68/head:pull/68

PR: https://git.openjdk.org/jdk20/pull/68