Fix a test

Locale.ROOT doesn't round trip -- it results in a langugage tag of
"und" (undefined, I suppose), and when you round-trip back you don't
get Locale.ROOT from it. The old test worked because it was
fundamentally just testing that the template script execution would
result in the expected string (whether or not you could actually do
anything with the Locale that would result), while this new test is
checking the round-trip behavior.

Author: joegallo

modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/DateProcessorFactoryTests.java

@@ -84,7 +84,7 @@ public void testParseLocale() throws Exception {
         String sourceField = randomAlphaOfLengthBetween(1, 10);
         config.put("field", sourceField);
         config.put("formats", List.of("dd/MM/yyyyy"));
-        Locale locale = randomFrom(Locale.GERMANY, Locale.FRENCH, Locale.ROOT);
+        Locale locale = randomFrom(Locale.GERMANY, Locale.FRENCH, Locale.CANADA);
         config.put("locale", locale.toLanguageTag());
 
         DateProcessor processor = factory.create(null, null, null, config, null);