title: Flutter plugin not installed error; When running 'flutter doctor'
body: <p>I am configuring the Flutter SDK on my Linux <a href="https://en.wikipedia.org/wiki/Ubuntu_version_history#Ubuntu_16.04_LTS_.28Xenial_Xerus.29" rel="noreferrer">Ubuntu 16.04</a> (Xenial Xerus) system. Why am I getting the following error when I run the flutter doctor?</p>
  <p>I have specified both <code>PATHS</code> for <code>flutter</code> and <code>dart</code> in the <code>.bashrc</code> file, but I get this error when I run <code>flutter doctor</code>:</p>
  <pre class="lang-none prettyprint-override"><code>Doctor summary (to see all details, run flutter doctor -v):
  [✓] Flutter (Channel beta, v0.5.1, on Linux, locale en_US.UTF-8)
  [✓] Android toolchain - develop for Android devices (Android SDK 28.0.2)
  [✓] Android Studio (version 3.1)
      ✗ Flutter plugin not installed; this adds Flutter specific functionality.
      ✗ Dart plugin not installed; this adds Dart specific functionality.
  [✓] IntelliJ IDEA Community Edition (version 2018.2)
  [!] VS Code (version 1.25.1)
  [!] Connected devices
      ! No devices available
  
  ! Doctor found issues in 2 categories.
  </code></pre>