I wouldn't like to rely on google translate as an accurate guide to pronunciation. In that case it sounds much more like a G, whereas I always thought of is as a much harder sound, almost a K, just as is so with most other French words starting with QU.
Yes, lots of French words in Swiss German, and in the past there used to be even more, but there is a tendency these days, especially among the younger generation, to susbtitute words from Hochdeutsch, which in my view is unfortunate as the peppering of French idioms gives Swiss German that certain poetry.
Mind you, some of these French words are pronounced in very un-French ways. Pneu is one that comes to mind, which in Swiss German is pronounced more like pnoy.
Depends which Swiss German -- here in Basel its p-neuh (pretty much the same as in French).
Adieu is a good one -- apart from the fact that the meaning in Swiss German is very different to that in French, here it's pronounced "ah-deh", unless you're terribly upper class, in which case it's the straight French "adieuh". The older generation sometimes uses adieu for hello as well as goodbye... quite confusing.
But Sihlquai is obviously not a dock and never was. The Sihl not even being a navigable river. In this case it means waterfront or river bank (as in also Limmatquai, Utoquai etc). This actually being the older if not original meaning, which later got to also mean a dock or mooring place, as in its English meaning (quay).
The word also has a Hochdeutsch cognate in the form of Kai (pronounced ka-ee), also having this meaning.
The origin of the word, apparently, is Celtic, and it entered the French language through Norman French.