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

[Mikhail Yankelevich]

> 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

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/23727/files
  - new: https://git.openjdk.org/jdk/pull/23727/files/aef7091b..2985d18f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23727&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23727&range=04-05

  Stats: 4 lines in 1 file changed: 1 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/23727.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23727/head:pull/23727

PR: https://git.openjdk.org/jdk/pull/23727