title: react-native-permissions returning RNPermissions null in react-native expo project
body: <p>I am new to Expo and I can't tell whats the problem here, I am good enough with Android and that I am trying to use the <a href="https://www.npmjs.com/package/react-native-qrcode-scanner" rel="noreferrer">react-native-qrcode-scanner</a> in a newly created blank react-native expo project. I haven't touched anything inside the project, just created a brand new project and I get an error saying <code>RNPermissions is null</code>. I think its telling to pass details about my android App, can anyone help me with how to start this? I am using <a href="https://github.com/react-native-community/react-native-permissions" rel="noreferrer">react-native-permissions</a> as its needed by the code of QR Code Scanner, I uninstalled everything in dependencies and left only these:</p>
  
  <pre><code>"dependencies": {
      "expo": "~36.0.0",
      "react": "~16.9.0",
      "react-dom": "~16.9.0",
      "react-native": "https://github.com/expo/react-native/archive/sdk-36.0.0.tar.gz",
      "react-native-permissions": "^2.0.2",
      "react-native-web": "~0.11.7"
  }
  </code></pre>
  
  <p>so there is just basic welcome to react message in App.js like this:</p>
  
  <pre><code>import React from 'react';
  import { StyleSheet, Text, View } from 'react-native';
  import { check, PERMISSIONS, RESULTS } from 'react-native-permissions';
  
  class App extends React.Component {
    constructor(props) {
      super(props);
    }
    render() {
      return (
        &lt;View style={styles.container}&gt;
          &lt;Text&gt;Open up App.js to start working on your app!&lt;/Text&gt;
        &lt;/View&gt;  
      );
    }
  }
  const styles = StyleSheet.create({
    container: {
      flex: 1,
      backgroundColor: '#fff',
      alignItems: 'center',
      justifyContent: 'center',     
    },
  });
  export default App;
  </code></pre>
  
  <p>THIS is the app.json file:</p>
  
  <pre><code>{
    "expo": {
      "name": "App1",
      "slug": "App1",
      "privacy": "public",
      "sdkVersion": "36.0.0",
      "platforms": [
        "ios",
        "android",
        "web"
      ],
      "version": "1.0.0",
      "orientation": "portrait",
      "icon": "./assets/icon.png",
      "splash": {
        "image": "./assets/splash.png",
        "resizeMode": "contain",
        "backgroundColor": "#ffffff"
      },
      "updates": {  
        "fallbackToCacheTimeout": 0
      },
      "assetBundlePatterns": [
        "**/*"
      ],
      "ios": {
        "supportsTablet": true
      }
    }
  }
  </code></pre>