<i18n dev> RFR: 8283842: TestZoneTextPrinterParser.test_roundTripAtOverlap fails: DateTimeParseException

[Naoto Sato]

Fixes test failures caused by depending on the default locale. Specifying explicit `Locale.US` will do.

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Commit messages:
 - 8283842: TestZoneTextPrinterParser.test_roundTripAtOverlap fails: DateTimeParseException

Changes: https://git.openjdk.java.net/jdk/pull/8045/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8045&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8283842
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8045.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8045/head:pull/8045

PR: https://git.openjdk.java.net/jdk/pull/8045