RFR: 8310182: DateTimeFormatter date formats (ISO_LOCAL_DATE) separated with hyphen, not dash

[Naoto Sato]

Replacing the ambiguous `dash` with `hyphen-minus` for more clarity. There are other locations than `ISO_LOCAL_DATE` that have the same description. Those are corrected too.

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Commit messages:
 - 8310182: DateTimeFormatter date formats (ISO_LOCAL_DATE) separated with hyphen, not dash

Changes: https://git.openjdk.org/jdk/pull/14620/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14620&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8310182
  Stats: 6 lines in 1 file changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/14620.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14620/head:pull/14620

PR: https://git.openjdk.org/jdk/pull/14620