[jdk11u-dev] RFR: 8274597: Some of the dnd tests time out and fail intermittently

[Goetz Lindenmaier]

I backport this for parity with 11.0.17-oracle.

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Commit messages:
 - Backport 669ac611b269bbda5c53d84173e5c9d0eb4ce919

Changes: https://git.openjdk.org/jdk11u-dev/pull/1437/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1437&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8274597
  Stats: 159 lines in 4 files changed: 107 ins; 12 del; 40 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1437.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev pull/1437/head:pull/1437

PR: https://git.openjdk.org/jdk11u-dev/pull/1437