Weird UI behavior of Text Input with Dark Mode

### Current behaviour

With Dark Mode on, some Text Input outlined are ok, others with same code have a white line on the label.

The code is the same for "Nome Garage*" and "Email":
```
setGarageDoc({...garageDoc, name: text})}
/>
```
```
setGarageDoc({ ...garageDoc, email: text })}
/>
```

The started value is undefined for both, I tried to change the order, modify the style, change the label name with so many tries and I still can't understand what is causing this behaviour.

This behaviour is shared in all part of my application where there is a Text Input oulined.

### Expected behaviour

I'd expect to not have a white line on Text Input label outlined in dark mode.

### Code sample

```

setGarageDoc({...garageDoc, name: text})}
/>
setGarageDoc({ ...garageDoc, email: text })}
/>

```
### What have you tried

This behaviour is all
### Your Environment

| software | version
| --------------------- | -------
| ios or android | android
| react-native | 0..67.3
| react-native-paper | 4.11.2
| node | 14.x
| npm or yarn | yarn
| expo sdk | no

まず、react-native-paper 4.11.2を使用して、Android上で説明されているTextInputのダークモード動作を再現します。その際、2つのラベル例と提供されているSafeAreaView/Cardコードを使用してください。2つの入力のレンダリングを比較し、TextInputの実装とテーマ関連のスタイリングを調査してください。ダークモードでoutlinedラベルが白い線なしに一貫してレンダリングされれば完了です。

索引モデルが issue の本文から書いたものです。