title: Unresolved Reference R after Androidx Migration
body: <p>After updating my dependencies in the build.gradle (Module: app) in Gradle Scripts, all my layout, strings,  all references that are defined by R are not available.  I have the following code in the Module app:</p>
  
  <pre><code>subprojects {
      project.configurations.all {
          resolutionStrategy.eachDependency { details -&gt;
              if (details.requested.group == 'com.android.support'
                      &amp;&amp; !details.requested.name.contains('multidex')) {
                  details.useVersion "28.0.0"
              }
  
              if(details.requested.group == 'androidx.lifecycle'  &amp;&amp; !details.requested.name.contains('multidex'))
              {
                  details.useVersion "2.0.0"
              }
  
          }
      }
  }
  
  dependencies 
  {
  
  
   implementation 'androidx.test:runner:1.1.0'
      implementation 'androidx.test.espresso:espresso-core:3.1.0'
          //    androidTestImplementation 'com.android.support.test:runner:1.0.2'
          //    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
  
      // lifecycle components
      implementation 'androidx.lifecycle:lifecycle-extensions:2.0.0'
      implementation 'androidx.lifecycle:lifecycle-viewmodel:2.0.0'
      implementation 'androidx.lifecycle:lifecycle-livedata-core:2.0.0'
      kapt 'androidx.lifecycle:lifecycle-compiler:2.0.0'
  
      //    implementation 'android.arch.lifecycle:extensions:1.1.1'
      //    kapt "android.arch.lifecycle:compiler:1.1.1"
  
      // room components
          //    implementation 'android.arch.persistence.room:runtime:1.1.1'
      implementation 'androidx.room:room-runtime:2.0.0'
  
      //    data binding components
      annotationProcessor "com.android.databinding:compiler:3.1.4"
      implementation 'io.reactivex.rxjava2:rxjava:2.2.2'
      implementation 'io.reactivex.rxjava2:rxandroid:2.1.0'
      implementation 'com.github.bumptech.glide:glide:4.8.0'
      annotationProcessor 'com.github.bumptech.glide:compiler:4.8.0'
  
      //implementation 'com.google.dagger:dagger-android:2.16'
      implementation 'com.google.dagger:dagger-android-support:2.16'
      // if you use the support libraries
      annotationProcessor 'com.google.dagger:dagger-android-processor:2.15'
      compile project(path: ':data')
  }
  </code></pre>
  
  <p>On searching the project, via the project explorer the project  no longer seems to have an R file.</p>