Fix forward_transfer test to match the updated API

[soareschen]

Summary

The forward_transfer test is failing on Gaia v8.0.0-rc3 in #3019. The likely reason for this is that the packet forward middleware has been updated with a new API as specified here.

The test needs to be fixed so that it works with the new version of the packet forward middleware.

As for whether to keep the original behavior on Gaia v6, my current understanding that there is no need for that, as the feature is not currently in use. However it would be good to double check whether we need to support both behaviors at the same time. Nevertheless, the support for v8 takes precedence over older versions.

---

For Admin Use

• Not duplicate issue
• Appropriate labels applied
• Appropriate milestone (priority) applied
• Appropriate contributors tagged
• Contributor assigned/self-assigned