Google_maps_flutter not showing zoom and route buttons in iOS

When using a google_map_flutter api in IOS, no zoom and route buttons are displayed. These buttons are showed in Android, when tapping in any place on the map. However, the same behavior is not present in IOS. I want that these buttons are available in IOS too. Only the button myLocation is displayed in IOS.

Here is the code snippet that I used to create Map.

    GoogleMap createGoogleMap(
      double latitude, double longitude, Set<Marker> markers) {

    return GoogleMap(
      mapType: MapType.normal,
      initialCameraPosition: initialPos,
      zoomControlsEnabled: true,
      onMapCreated: (GoogleMapController controller) {
        _controller.complete(controller);
        _googleMapController = controller;
      },
      markers: markers.isEmpty ? new Set<Marker>() : markers,
    );
  }