Box and unbox long values in state fields (#14176)

We actually want to pass around the primitive long values emulated by
GWT even though JavaScript code can't do anything with the values.
Skipping the unboxing caused long fields to always be 0 since that's how
JavaScript converts an object into a number.

This patch also makes the test assert that the expected state values are
received and updates those values to actually make sense in some
situations.

Change-Id: Id9c3696d699593bd9e59e249c5daf077873b85fc