[jdk21u-dev] RFR: 8311881: jdk/javax/swing/ProgressMonitor/ProgressTest.java does not show the ProgressMonitorInputStream all the time

[Goetz Lindenmaier]

I backport this for parity with 21.0.4-oracle.

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Commit messages:
 - Backport 197981b431fb7c7e6740ac45a671b99d1c7583c6

Changes: https://git.openjdk.org/jdk21u-dev/pull/460/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=460&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8311881
  Stats: 11 lines in 1 file changed: 6 ins; 1 del; 4 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/460.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/460/head:pull/460

PR: https://git.openjdk.org/jdk21u-dev/pull/460