react-navigation: Updated withNavigation HOC for suppressing prop requirement (#29208)

## Why?

Typescript requires assign of `navigation` on Component that is created with `withNavigation` HOC. But it comes with that function so it shouldn't require that property.

## Example

```typescript
//
// on the current version, this will give an error.
// with this PR, it will work.
//
interface IHelloProps extends Partial<NavigationInjectedProps> {
  hello: boolean;
}

const HelloBox: SFC<IHelloProps> = ({ navigation, hello }) => (
<View>
<TouchableHighlightCustom onPress={() => navigation.navigate('TEST', { hello })}>
        <Text>Hello</Text>
      </TouchableHighlightCustom>
</View>;
);

export default withNavigation(HelloBox);
```
----

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types/react-navigation/index.d.ts

@@ -1254,7 +1254,7 @@ export function withNavigation<T extends React.ComponentType<NavigationInjectedP
 
 // For backwards compatibility
 export function withNavigation<T = {}, P = NavigationParams>(
-  Component: React.ComponentType<T & NavigationInjectedProps<P>>,
+  Component: React.ComponentType<T | (T & NavigationInjectedProps<P>)>,
 ): React.ComponentType<T & { onRef?: React.Ref<React.Component<T & NavigationInjectedProps<P>>> }>;
 
 export interface NavigationFocusInjectedProps<P = NavigationParams> extends NavigationInjectedProps<P> {