RFR: 8328004: Minor updates to TrayIcon test DisposeInActionEventTest.java

[Phil Race]

This was recently converted from a manual Applet to a PassFailJFrame main program
But I see a few things that could be tweaked
 - Clarify instructions
 -  Set path to PassFailJFrame
 - reduce timeout to default
 - eliminate redundant folder

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Commit messages:
 - 8328004
 - 8328004

Changes: https://git.openjdk.org/jdk/pull/18246/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18246&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8328004
  Stats: 264 lines in 2 files changed: 133 ins; 131 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/18246.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18246/head:pull/18246

PR: https://git.openjdk.org/jdk/pull/18246