Determine whether Java needs to track unmanaged resources to free them for custom wallets

In the Java wrapper the callbacks to get values from a custom wallet type copy the strings from the managed JVM environment to unmanaged memory so the underlying SDK can access them and the SDK subsequently calls the free() callback in order to get the type to release the unmanaged resources. I'm concerned since the managed environment doesn't track the allocated resources there is a risk that under some circumstances, if the free() callback is not called (e.g. if the type was disposed by the managed environment before the callback) then some unmanaged resources may never be freed.