Fix PropertyChangeSupport problems.

The fire methods weren't delegating as the spec requires them to.

The serialization was absolutely broken. Serialization for this class
is completely wacky.

Handling of PropertyChangeEventProxy instances was also broken. This
fixes that also. The name of an added proxy filters the events that
are received by the listener.

http://b/2224874

Change-Id: I609f7bf65492264849b511e99b98092008c505d8