Unfortunately for everyone ... you can't. What you can do is, after you add a few contacts, use Import/Export in Settings in the Contacts menu to import all the SIM contacts to your Google account. Or hit the dropdown every time. (You'd think Google would want the Google account to be the default - and that they'd realize that saving contacts to the SIM card is from the stone age, when there wasn't any other place to save them but internal memory (which you lost if the phone went bad).