title: "resource android:attr/fontVariationSettings not found." in react-native
body: <p>I have a react-native project and it works ok yesterday for android, But error happens today when i run <code>react-native run-android</code>. Before I run it on android today ,nothing is changed,only open it in <code>AndroidStudio</code>. The Error as following:</p>
  
  <blockquote>
    <p>.gradle/caches/transforms-1/files-1.1/appcompat-v7-27.0.2.aar/d1dde4fd0fa50f7f7336597688c557a9/res/values/value
    s.xml:252:5-69: AAPT: error: resource
    android:attr/fontVariationSettings not found.</p>
    
    <p>.gradle/caches/transforms-1/files-1.1/appcompat-v7-27.0.2.aar/d1dde4fd0fa50f7f7336597688c557a9/res/values/value
    s.xml:252:5-69: AAPT: error: resource android:attr/ttcIndex not found.</p>
    
    <p>error: failed linking references.</p>
    
    <p>FAILURE: Build failed with an exception.</p>
    
    <ul>
    <li>What went wrong: Execution failed for task ':app:processDebugResources'.
    
    <blockquote>
      <p>Failed to process resources, see aapt output above for details.</p>
    </blockquote></li>
    </ul>
  </blockquote>
  
  <p>And the main config as the following:</p>
  
  <pre><code>"react": "16.6.3",
  "react-native": "0.57.8"
  
  gradle plugin:com.android.tools.build:gradle:3.1.0
  
  compileSdkVersion 27
  buildToolsVersion "27.0.3"
  minSdkVersion 19
  targetSdkVersion 27
  </code></pre>
  
  <p>I spent a lot of time to resolved it, but failed.</p>
  
  <p>Most resolutions are that upgrade android to AndroidX,But i cannot,because my prohect have many dependencies,and some of them are not support AndroidX.</p>
  
  <p>So I want to know <strong>why need <code>android:attr/ttcIndex</code></strong> when i run it.And how to fix it and donot upgapde android version and keep <code>compileSdkVersion 27</code></p>