[java] Add missing SimpleTimeZone members

[Tom Tromey]

>> One question I had was whether we needed updates to serialization to
>> account for this change.  Can you find out?

Jerry> How do I go about checking this?

Look at the reference javadoc, there is a link to "serialized form".
Then make sure we generate the right information; in particular this
class has readObject and writeObject, but looking there it seems
possible that more information might have been added...

Tom