RFR: 8041447: Test javax/swing/dnd/7171812/bug7171812.java fails with java.lang.RuntimeException: Test failed, scroll on drag doesn't work

[Prasanta Sadhukhan]

Test probably was failing few years back due to samevm mode.
It's not failing now but made some robot safeguards.
Several iterations are passing in all CI platforms. Link in JBS.

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Commit messages:
 - 8041447: Test javax/swing/dnd/7171812/bug7171812.java fails with java.lang.RuntimeException: Test failed, scroll on drag doesn't work

Changes: https://git.openjdk.org/jdk/pull/11959/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11959&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8041447
  Stats: 29 lines in 2 files changed: 16 ins; 4 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/11959.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11959/head:pull/11959

PR: https://git.openjdk.org/jdk/pull/11959