From my reading of the google sites documentation, it isn't possible to use the JS. api to embed. You can embed using the iframe gadget though.
Here is one on my site - test of cn embed - test of embed
i used the instructions found here - Embedded Views - Tableau User Group - AHC-IS Confluence
I hope that helps
Thanks Patrick. I figured it out just a moment ago. Essentially I just changed the vizURL to something like this:
Here's the documentation on Tableau: