Modals on iOS do not respond to the presence of the on-screen keyboard

### Current behaviour
On web and Android, the Modal component respects the state of the keyboard, adjusting it's height accordingly. On iOS, however, the Modal does not move up when the keyboard is opened.

This issue is likely related to [2172](https://github.com/callstack/react-native-paper/issues/2172)

### Expected behaviour
The Modal component should respect the positions of the keyboard and respond accordingly on all platforms.

### How to reproduce?
1. Add a Modal component inside a Portal component.
2. Add content to the Modal component and open the Modal.
3. Open the device on-screen keyboard on an iOS device.
4. Notice how the Modal doesn't respond (move up) to accommodate the keyboard, even though there is empty space available above the modal.

### Preview
iOS:

Android:

### What have you tried so far?
We're currently following the workaround listed [here](https://github.com/callstack/react-native-paper/issues/2172#issuecomment-725769818).

### Your Environment

| software | version
| --------------------- | -------
| ios | x
| android | x
| react-native | 0.71.14
| react-native-paper | 5.11.2
| node | 20.9.0
| npm or yarn | 10.1.0
| expo sdk | 48.0.20

在 iOS 设备上使用 Portal 内的 React Native Paper Modal，按照报告中的四个步骤复现该问题。将 iOS 的行为与 Android 以及 issue 2172 中讨论的 workaround 进行比较。完成标准是：在有可用空间时，Modal 会移动以适应屏幕键盘，同时不影响 web 或 Android 的行为。

由索引模型根据 Issue 内容生成。