RFR: 8291825: java/time/nontestng/java/time/zone/CustomZoneNameTest.java fails if defaultLocale and defaultFormatLocale are different

[Daniel Jeliński]

This patch fixes the test to use the same locale as the tested code

-------------

Commit messages:
 - CustomZoneNameTest fails if default locale does not match defaultFormatLocale

Changes: https://git.openjdk.org/jdk/pull/9729/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9729&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8291825
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/9729.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9729/head:pull/9729

PR: https://git.openjdk.org/jdk/pull/9729