Function
calculateCentroidSize
Common
```kotlin
fun PointerEvent.calculateCentroidSize(useCurrent: Boolean = true): Float
```
Returns the average distance from the centroid for all pointers that are currently and were
previously down. If no pointers are down, `0` is returned. If `useCurrent` is `true`, the size of
the `PointerInputChange.position` is returned and if `false`, the size of
`PointerInputChange.previousPosition` is returned. Only pointers that are down in both the
previous and current state are used to calculate the centroid size.
Example Usage: