Container padding cuts off switch shadow

### Problem description

When the switch's container has padding, it's shadow will be cut-off.

### Environment

- Tabris.js version: 2.5.1
- OS: iOS 11.4

### Code snippet

```javascript
const {Composite, Switch, ui} = require('tabris');

ui.contentView.append(
new Composite({left: 0, top: 0, padding: 30}).append(
new Switch({left: 0, top: 0})
)
);
```