<i18n dev> RFR: 8321206: Make Locale related system properties static properties

[Naoto Sato]

Currently, Locale-related system properties, such as `user.language` or `user.country`, are initialized when the `Locale` class is loaded. Making them static properties is safer than relying on the class initialization timing, which could potentially be changed depending on the implementation.

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Commit messages:
 - Add exclusions in cdsHeapVerifier for new StaticProperties
 - initial commit

Changes: https://git.openjdk.org/jdk/pull/16986/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16986&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8321206
  Stats: 183 lines in 3 files changed: 163 ins; 6 del; 14 mod
  Patch: https://git.openjdk.org/jdk/pull/16986.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16986/head:pull/16986

PR: https://git.openjdk.org/jdk/pull/16986