There is a mechanism to use tons of fake contacts by means of a test token. This should be generated by @jmcanterafonseca and the expired time for this one is 24 hours thought. Then, when you are sure that you will use it, you can ask him due to the token is not valid 24h after.

You should add the token here:

https://github.com/mozilla-b2g/gaia/blob/master/build/applications-data.js#L324

Thanks for you interest on it