How to make the `contentContainer` background transparent?

Nobody has claimed this yet.

### Question
How to make the `contentContainer` background transparent? As you can see it is the red part in the screen shot.
```
contentContainerCustomStyle={{
alignItems: 'center',
justifyContent: 'center',
backgroundColor: 'red'
}}
```

I have tried ` backgroundColor: 'red' -> backgroundColor: 'rgba(255, 0, 0, 0.5)'`, no luck, it becomes like this:


### Environment

Environment:
React: 16.13.1
React native: 0.63.2
react-native-snap-carousel: 3.9.1

Target Platform:
Android (N/A)
iOS (14.0)

(Write your answer here.)

### Expected Behavior
I expect the red part become transparent, and I am able to see the map behinds it, however it is not.

### Actual Behavior

It seems there is another white background that blocks the view to the true background
### Reproducible Demo

(Paste the link to a [Snack example](https://snack.expo.io/) in which the issue can be reproduced. Please follow [the guidelines](https://stackoverflow.com/help/mcve) for providing a Minimal, Complete, and Verifiable example.)

### Steps to Reproduce

(Write your steps so that anyone can reproduce the issue in the Snack demo you provided.)

1.
2.
3.

Start by reviewing the contentContainerCustomStyle usage in the react-native-snap-carousel documentation and reproducing the reported behavior with the React Native 0.63.2 and react-native-snap-carousel 3.9.1 versions. A useful outcome would be a documented, reproducible explanation of how the carousel background interacts with the map, or a clearly scoped change if the behavior is a library defect.

Written by the indexing model from the issue text.