RFR: 8340790: Open source several AWT Dialog tests - Batch 4 [v2]

[Tejesh R]

> Open source these AWT Dialog tests:
> 
> java/awt/Dialog/FileDialogGetFileTest.java
> java/awt/Dialog/EnabledResetTest.java
> java/awt/Dialog/ChoiceModalDialogTest.java
> java/awt/Dialog/DialogBackgroundTest.java

Tejesh R has updated the pull request incrementally with one additional commit since the last revision:

  Updated review comments

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Changes:
  - all: https://git.openjdk.org/jdk/pull/21404/files
  - new: https://git.openjdk.org/jdk/pull/21404/files/b9b98827..e8612332

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21404&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21404&range=00-01

  Stats: 7 lines in 4 files changed: 0 ins; 1 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/21404.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21404/head:pull/21404

PR: https://git.openjdk.org/jdk/pull/21404