[coheigea]

When no rule applied to a method's signature, every role annotation
recorded for its name applied. A method implementing a generic
interface method, whose erased signature differs, therefore needed the
roles of every method with the same name, an unannotated overload
needed the roles of its annotated overloads, and an implementation's
class-level @RolesAllowed, which applies to its own signature, hid the
method-level @RolesAllowed of the generic interface method.

As in OAuthScopesFilter and ClaimsAuthorizingInterceptor, the generic
parameter types of the superclass and interface methods are now
resolved against the class's type arguments
(ReflectionUtil.getGenericallyOverriddenMethods), so a method also gets
the rules of exactly the generic methods it overrides, and the
name-based fallback is only used for methods which are not part of the
secured object.

[ffang]

Thanks @coheigea, LGTM. Matching a method only to the generic methods it actually overrides, as OAuthScopesFilter and ClaimsAuthorizingInterceptor already do, fixes a real gap: an implementation's class-level @RolesAllowed no longer hides the method-level @RolesAllowed of the generic interface method. Core tests pass with -Psourcecheck, and all six new tests fail against the current interceptor.

Just one Nit: getGenericallyOverriddenMethods rebuilds the type-argument map of the whole class hierarchy for every method, and findRoles calls it for every class in the hierarchy. It only runs at setup, so it doesn't matter much, though the map could be computed once per class.