Disable SwitchCell tap on iOS

[yk4to]

In this library, onSwitch event is called both when the SwitchCell itself and the switch are pressed.

In the native applications of both OS, In Android's ListView, the switch is also toggled when the cell is pressed, but in iOS' UITableView, it is only toggled when the Switch itself is pressed.

So I made a small change so that the event is called by tapping the SwitchCell itself only on Android.