RFR: 8349533: Refactor validator tests shell files to java [v6]

[Weijun Wang]

On Mon, 24 Feb 2025 20:08:12 GMT, Mikhail Yankelevich <duke at openjdk.org> wrote:

>> Changed shell files to be java tests:
>> * ./validator/certreplace.sh
>> * ./validator/samedn.sh
>
> Mikhail Yankelevich has updated the pull request incrementally with one additional commit since the last revision:
> 
>   missing close file

Marked as reviewed by weijun (Reviewer).

-------------

PR Review: https://git.openjdk.org/jdk/pull/23727#pullrequestreview-2638364290