RFR: 4512626: Non-editable JTextArea provides no visual indication of keyboard focus

[Alexander Zuev]

Set the text caret to be visible but not blinking on the non-editable text area.

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Commit messages:
 - 4512626: Non-editable JTextArea provides no visual indication of keyboard focus

Changes: https://git.openjdk.org/jdk/pull/11408/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11408&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-4512626
  Stats: 13 lines in 1 file changed: 11 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/11408.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11408/head:pull/11408

PR: https://git.openjdk.org/jdk/pull/11408