When passing the Google User ID as the login_hint property of the gapi.auth2.authorize no account is preselected. Instead the whole list of user accounts is displayed. It only works when providing the User Email Address instead of his User ID contrary to what is explained in the documentation:
The email, or User ID, of a user to pre-select in the sign-in flow. This is susceptible to modification by the user, unless prompt: "none" is used.
Note that I checked that the User ID was valid (and in my case it is provided by the Google Drive UI integration as the userId parameter)