on
          Allows you to implement or observe the map scale gesture handler. The surface is onAttached before this can be triggered.
See also
androidx.
SurfaceCallback#onScalefor instructions to enable.
Parameters
mapbox
loaded and ready car map surface
focus
x coordinate of the focal point in pixels. A negative value indicates that the focal point is unavailable.
focus
y coordinate of the focal point in pixels. A negative value indicates that the focal point is unavailable.
scale
the scaling factor from the previous state to the current state during the scale event. This value is defined as (current state) / (previous state)