RFR: 8338488: Add screen capture for failure case

[Tejesh R]

open/test/jdk/java/awt/Checkbox/CheckboxCheckerScalingTest.java is failing intermittently on Linux (https://bugs.openjdk.org/browse/JDK-8338153). As part of analysis I've updated the test with image writing on failure condition.

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Commit messages:
 - Updated the test with image write on failure

Changes: https://git.openjdk.org/jdk/pull/20614/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20614&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8338488
  Stats: 10 lines in 1 file changed: 10 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/20614.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20614/head:pull/20614

PR: https://git.openjdk.org/jdk/pull/20614