Fix integration test using the default Locale in Locale#getDisplayName() (#2611)
Fix integration test using the default Locale in Locale#getDisplayName() (#2611)

The integration test was checking if DataFetchingEnvironment#getLocale()#getDisplayName() returned "German" when the locale passed to the ExecutionInput was Locale.GERMAN. This commit changes the call to getDisplayName(Locale.ENGLISH). Making sure the system locale doesn't affect the test.
graphql-java/graphql-java,graphql-java/graphql-java