title: How to fix "Android license status unknown" in flutter
body: <p>my flutter doctor -v result:</p>
  
  <pre><code>[√] Flutter (Channel stable, v1.0.0, on Microsoft Windows [Version 10.0.17134.472], locale fa-IR)
      • Flutter version 1.0.0 at C:\Android\flutter
      • Framework revision 5391447fae (6 weeks ago), 2018-11-29 19:41:26 -0800
      • Engine revision 7375a0f414
      • Dart version 2.1.0 (build 2.1.0-dev.9.4 f9ebf21297)
  
  [!] Android toolchain - develop for Android devices (Android SDK 27.0.3)
      • Android SDK at c:\Android\android-sdk
      • Android NDK location not configured (optional; useful for native profiling support)
      • Platform android-28, build-tools 27.0.3
      • ANDROID_HOME = C:\Android\android-sdk
      • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
      • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)
      X Android license status unknown.
  
  [√] Android Studio (version 3.1)
      • Android Studio at C:\Program Files\Android\Android Studio
      • Flutter plugin version 29.0.1
      • Dart plugin version 173.4700
      • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)
  
  [√] Connected device (1 available)
      • HUAWEI CUN U29 • CCMBBCB6C0153603 • android-arm • Android 5.1 (API 22)
  </code></pre>
  
  <p>and when run: </p>
  
  <pre><code>flutter doctor --android-licenses
  </code></pre>
  
  <p>get me this result:</p>
  
  <pre><code>A newer version of the Android SDK is required. To update, run:
  c:\Android\android-sdk\tools\bin\sdkmanager --update 
  </code></pre>
  
  <p>and when update sdkmanager show this error to me:</p>
  
  <pre><code> Exception in thread "main" java.lang.NoSuchFieldError: FN_AAPT2
          at com.android.sdklib.BuildToolInfo.&lt;init&gt;(BuildToolInfo.java:362)
  </code></pre>
  
  <p>How can i solve this challenge?</p>