I'm not sure. In the case of *Midler v. Ford Motor Co.*, the advertising agency hired a singer to do an impression of Bette Midler herself, not a character she performs. The singer was instructed to sound as much like Bette Midler as possible while performing her hit song "Do You Want to Dance?" for the Ford commercial. This use of a sound-alike voice led to the lawsuit, as it mimicked Midler's distinctive voice without her permission.
Scarlett Johansson's character in the movie is not Scarlett Johansson although her voice is very similar. I wouldn't say it's identical.
I haven't seen the commercial, but I feel like it's also probably not identical. My read of the case is that the context connecting Midler to the ad without her consent was a key feature, which makes me think Scarlett Johansson would be in a similarly strong position if she brought a case.
But ultimately I'm also not sure. There are some differences that courts could find important. I hope she sues and refuses to settle, so we can find out!
Scarlett Johansson's character in the movie is not Scarlett Johansson although her voice is very similar. I wouldn't say it's identical.