RFR: 8345547: test/jdk/javax/swing/text/DefaultEditorKit/4278839/bug4278839.java fails in ubuntu22.04

[Prasanta Sadhukhan]

test/jdk/javax/swing/text/DefaultEditorKit/4278839/bug4278839.java tests movement of caret between word and fails in OCI citing


java.lang.RuntimeException: Test failed.
at bug4278839.main(bug4278839.java:92)

which suggests caret is not moved as per expectation..It also seems the focus is not in the frame when the test start executing.
Added robot delay and waitForIdle and it passed in several OCI systems

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Commit messages:
 - test fix

Changes: https://git.openjdk.org/jdk/pull/22566/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22566&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8345547
  Stats: 21 lines in 1 file changed: 3 ins; 10 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/22566.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22566/head:pull/22566

PR: https://git.openjdk.org/jdk/pull/22566