Add this to the bottom of your settings_scheme.json

gp_settings_schema_addition

,
  {
    "name": "Google Places Autocomplete",
    "settings": [
      {
        "type": "header",
        "content": "Google Places Autocomplete"
      },
      {
        "type": "paragraph",
        "content": "Adds Google Places autocomplete to customer information and billing address forms in checkout."
      },
      {
        "type": "paragraph",
        "content": "To retrieve addresses from Google, you will need to provide an API key that can access both the Google Maps JavaScript API and the Google Places API Web Service.  Create a project for free at [Google's API Manager](https://console.developers.google.com/apis/)."
      },
      {
        "type": "checkbox",
        "id": "gp_enable_google_autocomplete",
        "label": "Enable Google Places autocomplete modification",
        "default": true,
        "info": "This will leverage Google Maps API to autocomplete address inputs."
      },
      {
        "type": "checkbox",
        "id": "gp_enable_geolocate",
        "label": "Enable Geolocate",
        "default": true,
        "info": "Biases address results to the customer's IP address' geographical location"
      },
      {
        "type": "text",
        "id": "gp_add_merchant_api_key",
        "label": "Add a store specific API key",
        "info": "The API key is necessary for communicating with the Google Places API."
      }
    ]
  }