SafeAreaView can't be transparent

Hello,

I began to switch from react-navigation SafeAreaView to your lib, and I'm experiencing a weird behavior.
With the older SafeAreaView we could obtain a 'transparent' view to pad the notch but your library seems to force a colored view, even if provide `backgroundColor: 'transparent'` to the SafeAreaView component, the background is still white.
And this view hide the content when we scroll for example.

With the react-navigation SafeAreaView:

With your SafeAreaView component:

I use this implementation

``` javascript

{this.renderBody()}
{this.renderTabBar()}

```

I searched a lot and I didn't found any reason and I'm asking myself if I'm not doing something wrong because any
one reported this bug. Could you please help me to use your library for my case ?

I tested it on Iphone X & 12