Make the PreFilter annotation support filtering of an immutable list.

I'm working on a web application where I have a service method

    @PreFilter("@securityAccessRightsBean.doesHaveDeleteRights(filterObject)")
    public List<String> removeObjects(List<String> objectIds) {
        // impl here
    }

and a controller that handles special flow for single objects, result ing in the use of the java.lang utility method

    Collections.singletonList(singleObjectId)

which eventually becomes the `filterObject`. However, that results in an `UnsupportedOperationException`, due to the `filterObject` being mutated. I vote to support filtering immutable lists (see that added unit test) with this pull request.

Note I only ran the core modules unit tests.