Run 180_locale_dependent_mapping only since 6.8.5 (#49724)

closes #49719

Author: pgomulka

rest-api-spec/src/main/resources/rest-api-spec/test/search/180_locale_dependent_mapping.yml

@@ -1,8 +1,8 @@
 ---
 "Test Index and Search locale dependent mappings / dates":
   - skip:
-      version: "all"
-      reason: "Awaits fix: https://github.com/elastic/elasticsearch/issues/49719"
+      version: " - 6.8.4"
+      reason: JDK9 only supports this with a special sysproperty added in 6.2.0 and the fix for avoiding multiple 8 prefix is in 6.8.5
   - do:
       indices.create:
           index: test_index