RFR: 8346581: JRadioButton/ButtonGroupFocusTest.java fails in CI on Linux

[Alexey Ivanov]

**Problem:**

The `javax/swing/JRadioButton/ButtonGroupFocus/ButtonGroupFocusTest.java` test fails in CI on Linux.

The focus is on _Button 2_ instead of _Button 4_.

**Root cause:**

The additional logging revealed, an expected `KEY_PRESS` event. The test uses `Robot` API to press the <kbd>Tab</kbd> key and release it. When the test fails, there are two `KEY_PRESS` events followed by a single `KEY_RELEASE` event. Because the <kbd>Tab</kbd> key is pressed twice, the focus moves twice: from _Button 2_ (the initial state) to _Button 4_ and then back to _Button 2_.

**Fix:**

Use `CountDownLatch`es to track whether a radio button received focus. Detect the case where two `KEY_PRESS` events moved focus to _Button 2_ and report the failure.

Log focus movements and dispatched key events to facilitate failure analysis.

Take a screenshot of the test frame in case of failure.

These CI hosts seem to be quite slow, removing the delay added by `robot.setAutoDelay(100)` has reduced the number of unexpected `KEY_PRESS` events. This didn't affect Windows or macOS.

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Commit messages:
 - Log only focusOwner properties to reduce the noise in the test log
 - Increase focus timeout and remove delay between generating events
 - Detect spurious KEY_PRESS event and report an error
 - Rework JRadioButton/ButtonGroupFocusTest.java

Changes: https://git.openjdk.org/jdk/pull/22977/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22977&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8346581
  Stats: 135 lines in 1 file changed: 96 ins; 13 del; 26 mod
  Patch: https://git.openjdk.org/jdk/pull/22977.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22977/head:pull/22977

PR: https://git.openjdk.org/jdk/pull/22977