We have hardcoded Unix-style newlines in PluginInfo.toString. We should use `System.lineSeparator()` instead.
server/src/main/java/org/elasticsearch/plugins/PluginInfo.java
if (type == PluginType.BOOTSTRAP) {
            if (Strings.isNullOrEmpty(classname) == false) {
                throw new IllegalArgumentException(
                    "property [classname] can only have a value when [type] is set to [bootstrap] for plugin [" + name + "]"
                );
            }
            return "";
        }
        if (classname == null) {
            throw new IllegalArgumentException("property [classname] is missing for plugin [" + name + "]");
        }
        return classname;
    }
    private static boolean parseBooleanValue(String pluginName, String name, String rawValue) {
        try {
            return Booleans.parseBoolean(rawValue, false);
        } catch (IllegalArgumentException e) {
            final String message = String.format(
                Locale.ROOT,
                "property [%s] must be [true], [false], or unspecified but was [%s] for plugin [%s]",
                name,
                rawValue,
                pluginName
            );
            throw new IllegalArgumentException(message);
        }
    }
    /**
     * The name of the plugin.
     *