RadioButton.Item - Android Talkback can reach radio button twice

### Current behaviour
If you use the Android Talkback screenreader to navigate the radio button, you first hit the label + radio button (as intended with `RadioButton.Item` - but then the screen reader can also reach the radio button itself, which is unlabelled. This is undesirable, as it's both confusing, and requires extra swiping.

### Expected behaviour
Radio button should not be reachable on its own when used within a `RadioButton.Item`.

### How to reproduce?
Create a `RadioButton.Item` and test it out with Android Talkback.

### Preview

### What have you tried so far?

### Your Environment

| software | version
| --------------------- | -------
| ios | x
| android | 16
| react-native | 0.81.5
| react-native-paper | 5.15.0
| node | x.x.x
| npm or yarn | x.x.x
| expo sdk | x.x.x

首先定位 RadioButton.Item 的实现，并使用 Android Talkback 重现该行为。跟踪该项及其 radio button 如何暴露给无障碍导航，然后验证 Talkback 只会到达组合标签和 radio button 一次。

由索引模型根据 Issue 内容生成。