title: android aapt error:no layout_constraintLeft_toLeftOf
body: <p>when i use aapt comandline to generate .R file for a new created android project,it shows that</p>
  
  <p><code>
  No resource identifier found for attribute 'layout_constraintLeft_toLeftOf' in package 'com.test.androidpack'
  </code></p>
  
  <p>so,how to contain constraint-layout in aapt command line? </p>
  
  <p>my command line is as below:
  <code>
  aapt package -f ^
  -M C:\Users\Administrator\Desktop\test\AndoidPack\app\src\main\AndroidManifest.xml ^
  -I D:\Android\Sdk\platforms\android-27\android.jar ^
  -S C:\Users\Administrator\Desktop\test\AndoidPack\app\src\main\res ^
  -J gen ^
  -m
  </code>
  and I tried add <code>-I xxxx\constraint-layout-1.1.1.aar</code>,<code>-j constraint-layout-1.1.1.aar</code>,all failed</p>