DROOLS-576 NullPointerException in ActivationTimerInputMarshaller.deserialize()
- Test case

(cherry picked from commit e560c722d3d2a6e159176e89c21b68b48b2fcce2)
(cherry picked from commit a995f2f75e8d0e39ef1c118591b8469e4fdfc0c9)
[DROOLS-576] avoid NPE in Timer deserialization

(cherry picked from commit 3b42da02cf6ab4d3bedb40b637ab6df494f13e64)