Summary:
**Description**
In the same vein as https://github.com/facebook/react-native/pull/11198, this adds a mock for the native module `AppState`.
**Test plan**
Create a component that uses `AppState`, e.g.
```jsx
import React, { Component } from 'react';
import { AppState } from 'react-native';
class TestComponent extends Component {
componentDidMount() {
AppState.addEventListener('change', this.stateChangeListener);
}
}
```
Closes https://github.com/facebook/react-native/pull/11199
Differential Revision: D4246668
Pulled By: cpojer
fbshipit-source-id: e3a73a98963a0e152a70aba78ef3461b86da0f6c
Summary:
Fixes warnings such as `Warning: Native component for "RCTView" does not exist` when you don't mock the native view class on `UIManager`.
**Test plan (required)**
Run `npm test` with it and without it, notice that warnings are gone and results are the same.
cc cpojer
Closes https://github.com/facebook/react-native/pull/10486
Differential Revision: D4063500
Pulled By: cpojer
fbshipit-source-id: f6bdda1fdd1ad87958f435071d353684cb812af4
