RFR: 8327486: java/util/Properties/PropertiesStoreTest.java fails "Text 'xxx' could not be parsed at index 20" after 8174269

[SendaoYan]

The DATE_FORMAT_PATTERN is set to "EEE MMM dd HH:mm:ss zzz uuuu", is the time format of US. So, creates a formatter should using Locale.US, rather than Locale.ROOT, which means empty.

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Commit messages:
 - 8327486: java/util/Properties/PropertiesStoreTest.java fails "Text 'xxx' could not be parsed at index 20" after 8174269

Changes: https://git.openjdk.org/jdk/pull/18155/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18155&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8327486
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/18155.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18155/head:pull/18155

PR: https://git.openjdk.org/jdk/pull/18155