title: Migrating AndroidX run error android.support.annotation does not exist
body: <p>I just have migrated my project to AndroidX. Sync and build phase are ok, but when I try to run the compiler show me this error:</p>
  
  <pre><code>error: package android.support.annotation does not exist
  </code></pre>
  
  <p>This error raises on a builded file </p>
  
  <pre><code>// Generated code from Butter Knife. Do not modify!
  package com.xdatanet.cda.Adapters;
  
  import android.support.annotation.CallSuper; //&lt;-- Doesn't exists
  import android.support.annotation.UiThread; //&lt;-- Doesn't exists
  import android.view.View;
  import android.widget.ImageView;
  import butterknife.Unbinder;
  import butterknife.internal.Utils;
  import com.xdatanet.cda.CustomView.CDATextView;
  import com.xdatanet.cda.R;
  import java.lang.IllegalStateException;
  import java.lang.Override;
  
  public class CommunicationAdapter$CommunicationViewHolder_ViewBinding implements Unbinder {
    private CommunicationAdapter.CommunicationViewHolder target;
  
    @UiThread  //&lt;-- First error
    public CommunicationAdapter$CommunicationViewHolder_ViewBinding(CommunicationAdapter.CommunicationViewHolder target,
        View source) {
        // Some generated code
    }
  
    @Override
    @CallSuper //&lt;-- Second error
    public void unbind() {
        // Some generated code
    }
  }
  </code></pre>
  
  <p>Gradle properties </p>
  
  <pre><code>android.enableJetifier=true
  android.useAndroidX=true
  </code></pre>
  
  <p>Butterknife implementation into gradle</p>
  
  <pre><code>implementation "com.jakewharton:butterknife:8.8.1"
  annotationProcessor "com.jakewharton:butterknife-compiler:8.8.1"
  </code></pre>
  
  <p>The IDE says <code>Files under the "build" folder are generated and should not be edited.</code></p>
  
  <ul>
  <li>Android Studio 3.2.1</li>
  <li>Min Sdk 19, Max Sdk 28</li>
  <li>Gradle version 3.2.1</li>
  </ul>
  
  <p>It seems to be an error with butterknife but I don't know why.</p>