Missing documentation for `preferPrivateSession` when calling `signInWithRedirect()`

**Describe the content issue**:

It looks like we missed documentation tied to the `signInWithRedirect` when trying to use `preferPrivateSession` for React Native. API would look like the following:

`signInWithRedirect({ preferPrivateSession: true });`

Feature is already available and supported in JS - https://github.com/aws-amplify/amplify-js/blob/main/packages/auth/src/types/inputs.ts#L58-L67

Came up as a question related to [Issue #4836](https://github.com/aws-amplify/amplify-ui/issues/4836) on UI repo (feature request for that repo at time of opening).

**URL page where content issue is**: