Cleanup unnecessary null comparison before instanceof check in security modules

Update code checks both non-null and instance of a class in security classes.
The checks and explicit casts could also be replaced with pattern matching for the instanceof operator.
For example:
    The following code:
    public boolean equals(Object obj) {
        if (obj == null || (!(obj instanceof AccessDescription))) {
            return false;
        }
        AccessDescription that = (AccessDescription)obj;
    Can be simplified to:
    public boolean equals(Object obj) {
        if (!(obj instanceof AccessDescription that)) {
            return false;
        }