<i18n dev> RFR: 8175709: DateTimeFormatterBuilder.appendZoneId() has misleading JavaDoc

[Naoto Sato]

Clarifying the documentation of `DateTimeFormatterBuilder.appendZoneId()` and similar methods to align the description with the behavior, in which `ZoneOffset` is only parsed from the formatter for offset texts without any prefixes. Corresponding CSR has also been drafted.

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Commit messages:
 - initial commit

Changes: https://git.openjdk.org/jdk/pull/22837/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22837&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8175709
  Stats: 34 lines in 1 file changed: 0 ins; 0 del; 34 mod
  Patch: https://git.openjdk.org/jdk/pull/22837.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22837/head:pull/22837

PR: https://git.openjdk.org/jdk/pull/22837