RFR: 8327492: Remove applet usage and update DisposeInActionEventTest.html [v15]

[Alisen Chung]

> Root cause of the test failure was fixed with https://bugs.openjdk.org/browse/JDK-8316931, updating this test since the other fix also included a test update.

Alisen Chung has updated the pull request incrementally with one additional commit since the last revision:

  update test instructions, fix spacing

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Changes:
  - all: https://git.openjdk.org/jdk/pull/17838/files
  - new: https://git.openjdk.org/jdk/pull/17838/files/0947ce09..3cb76575

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17838&range=14
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17838&range=13-14

  Stats: 4 lines in 2 files changed: 1 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/17838.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17838/head:pull/17838

PR: https://git.openjdk.org/jdk/pull/17838