I too was surprised to find the swastikas as part of the decor. I did a little research via google and it's definitely a pretty standard element in Mesoamerican art.
The strangest part was that they were not the familiar equilateral swastikas found in Nazi propaganda. Rather, the version in the Sutter St. building was composed of three fish-hook shapes & one capital L shape:
This was consistent for all of the "swastikas" throughout the building, as far as I could tell. What on earth it means, I have no idea.