<i18n dev> RFR: 8348205: Improve cutover time selection when building available currencies set

[Justin Lu]

Please review this PR which improves the time measurement for cut-over time comparisons when building the available set of currencies in _java.util.Currency._ Currently, a new time was measured for each special case currency. This PR updates the behavior to use the same time for all such cases

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Commit messages:
 - init

Changes: https://git.openjdk.org/jdk/pull/23309/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23309&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8348205
  Stats: 4 lines in 1 file changed: 2 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/23309.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23309/head:pull/23309

PR: https://git.openjdk.org/jdk/pull/23309