RFR: 8343220: Add test cases to AppContentTest jpackage test [v4]

[Alexander Matveev]

On Thu, 23 Oct 2025 21:14:41 GMT, Alexey Semenyuk <asemenyuk at openjdk.org> wrote:

>> - Update AppContentTest by adding new test cases as requested in the CR.
>> - Fix uncovered issue in jpackage: if the same path in the app image is sourced from a file and a directory values of `--app-content` option, it bails out trying to replace the file with the directory and vice versa.
>
> Alexey Semenyuk has updated the pull request incrementally with one additional commit since the last revision:
> 
>   AppContentTest: fix test failure on Windows

Looks good.

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Marked as reviewed by almatvee (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/27948#pullrequestreview-3373295122