<i18n dev> RFR: 8347146: Convert IncludeLocalesPluginTest to use JUnit [v2]

[Naoto Sato]

> A simple refinement to the test makes diagnosing failures easier.

Naoto Sato has updated the pull request incrementally with one additional commit since the last revision:

  Addresses review comments

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/23016/files
  - new: https://git.openjdk.org/jdk/pull/23016/files/ac7f72f5..47289b51

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23016&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23016&range=00-01

  Stats: 10 lines in 1 file changed: 2 ins; 5 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/23016.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23016/head:pull/23016

PR: https://git.openjdk.org/jdk/pull/23016