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

iOS デバイス上で Portal 内に配置した React Native Paper Modal を使って、報告にある 4 つの手順に従い問題を再現します。iOS の動作を Android および issue 2172 で議論されている workaround と比較します。十分な空きがある場合に、画面上のキーボードに合わせて Modal が移動し、web や Android の動作を後退させないことを完了条件とします。

索引モデルが issue の本文から書いたものです。