How do I indicate VMX file Guestinfo Variable Creation During OVA Build or within OVF?

After an OVA is deployed, it is possible to "hardcode" persistent VMware guestinfo variables by appending them to the VM's vmx file, as explained here:

http://www.virtuallyghetto.com/2011/01/how-to-extract-host-information-from.html (Option 1)

I've been able to do this by:

1.  Deploying an OVA created from VMware Studio using vSphere client without powering on.

2.  Downloading the vmx file from the created virtual machine and appending the desired variable, eg:

guestinfo.myapp.variable="initial-value"

3.  Uploading the vmx file back to the original location.

4.  Powering on the VM.

Now I can use the conventional VMware tools utilities to read and write persistently.

vmtoolsd --cmd "info-get guestinfo.myapp.variable"

vmtoolsd --cmd "info-set guestinfo.myapp.variable new-value"

Updated values remain persistent after power-off or reboot which is exactly what I need.

So how to I tell VMware Studio at OVA build time, or specify in the OVF file before deployment that I want guestinfo.myapp.variable to be created in the VM's vmx file?