title: Flutters Android Java source shows errors in IntelliJ
body: <p>I created a default Flutter project and opened it in IntelliJ. The IOS part works. On the Android site I get the following errors when I try to build the android module in IntelliJ. It seems to work if I open the android module in Android Studio alone (by using the menu item 'Open Android module in Android Studio'). Is this expected ?</p>
  
  <pre><code>Error:(3, 18) java: package android.os does not exist
  Error:(5, 22) java: package io.flutter.app does not exist
  Error:(8, 35) java: cannot find symbol
    symbol: class FlutterActivity
  Error:(10, 27) java: cannot find symbol
    symbol:   class Bundle
    location: class com.yourcompany.helloflutter.MainActivity
  Error:(9, 3) java: method does not override or implement a method from a supertype
  Error:(11, 5) java: cannot find symbol
    symbol:   variable super
    location: class com.yourcompany.helloflutter.MainActivity
  /Users/roger/Documents/hello_flutter/android/app/src/main/java/io/flutter/plugins/GeneratedPluginRegistrant.java
  Error:(3, 32) java: package io.flutter.plugin.common does not exist
  Error:(9, 35) java: cannot find symbol
    symbol:   class PluginRegistry
  </code></pre>