[jdk25u] RFR: 8369050: DecimalFormat Rounding Errors for Fractional Ties Near Zero

[Roland Mesde]

Backporting JDK-8369050: DecimalFormat Rounding Errors for Fractional Ties Near Zero. Fixes rounding logic, updates a test and adds a test. Ran GHA Sanity Checks (passed) and adjusted tests (passed).

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Commit messages:
 - Backport 376d77e8a71478f456af5baaf47f446eebd79e36

Changes: https://git.openjdk.org/jdk25u/pull/371/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u&pr=371&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8369050
  Stats: 95 lines in 3 files changed: 88 ins; 5 del; 2 mod
  Patch: https://git.openjdk.org/jdk25u/pull/371.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u.git pull/371/head:pull/371

PR: https://git.openjdk.org/jdk25u/pull/371