Well i don’t know much about contact form 7 , But if it works based on post types you should be able to do this :
You should write a function that runs after theme installation,This function can be written in 2 ways :
1. Insert new contact forms as posts with wp_insert_post() function,
http://codex.wordpress.org/Function_Reference/wp_insert_post
2. Import an XML after theme activation( honestly i don’t know if it’s possible )
