Update StringToEnumConverterFactory to search superclasses until
Class.isEnum() returns true. This allows conversion when the
enum class is obtained from the enum value:
public static enum SubFoo {
BAR { String s() { return "x"; } };
abstract String s();
}
conversionService.convert("BAR", SubFoo.BAR.getClass())
This fix is particularly important when converting collections of
enums.
Issue: SPR-10329