So that would mean that the person asking the bot to give consent or would that mean Google is the one giving consent? Or is the person giving permission to Google to give consent? Would Google give permission to the recording of the call?
I believe generally the US courts have decided that the person who triggers the action is the pertinent party.
Something similar has come up in the firearm fabrication community. There are companies that sell things that are legally paperweights, but are 80% of the way towards being a firearm (e.g. [1]). There are CNC mills that come with programming to take one of these "80% lowers" and finish it, making a fully functional firearm, or at least the part that is considered a firearm by the BATF; other parts can be ordered and shipped online (e.g. [2]).
In this case it's not the builder of the machine or the writer of the code that instructs it that is the "manufacturer" of the gun. It's not even the person who placed the unfinished lower in the enclosure and bolted it down. Instead it's the person who pushed that button.
I'm going to guess that this will be similar. The user who pushes the button (or asks assistant to make an appointment on their behalf) is likely to be the one giving consent.
But neither the laws nor the judges will be uniform. The laws use different words to say slightly different things, and will have different legislative histories (the record from the officials who voted them into law).
Some judges will look to the actual words to interpret the law, and others will look to the legislative history. Still others might desire a "living Constitution" approach — applying the laws in a way that they think makes sense in today's world.
Considering the dozens of laws and thousands of judges that could opine, there will likely be considerable uncertainty in this area for years to come.