title: kotlinx.android.synthetic unused android studio issue
body: <p>I am working one project using kotlin + Rxjava + MVVM. During development facing issue of importing view ids in Fragment or viewholder. </p>
  
  <p><code>import kotlinx.android.synthetic.main.layout.*</code> unused with kotlin.</p>
  
  <p><a href="https://i.stack.imgur.com/nrjL6.png" rel="noreferrer"><img src="https://i.stack.imgur.com/nrjL6.png" alt="kotling synthetic imports is unused"></a></p>
  
  <p>Normaly view id should used from kotlin synthetic layout imports but it directly import it from R.id that should not happen.</p>
  
  <p>Kotlin plugin version : <code>org.jetbrains.kotlin:kotlin-gradle-plugin:1.2.40</code></p>
  
  <p><strong>My gradle file</strong> : </p>
  
  <pre><code>apply plugin: 'com.android.feature'
  apply plugin: 'kotlin-android'
  apply plugin: 'kotlin-android-extensions'
  apply plugin: 'idea'
  apply plugin: 'kotlin-kapt'
  
  android {
      compileSdkVersion 27
      baseFeature true
      defaultConfig {
          minSdkVersion 23
          targetSdkVersion 27
          versionCode 1
          versionName "1.0"
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  
  
      lintOptions {
          abortOnError false
      }
  }
  
  dependencies {
  
      api "com.android.support:design:$rootProject.support_library_version"
      api "com.android.support:appcompat-v7:$rootProject.support_library_version"
      api "com.android.support:recyclerview-v7:$rootProject.support_library_version"
      api "com.android.support:support-dynamic-animation:$rootProject.support_library_version"
      api "com.android.support:cardview-v7:$rootProject.support_library_version"
      api "com.android.support:customtabs:$rootProject.support_library_version"
  
      api "com.android.support.constraint:constraint-layout:1.1.0-beta5"
      api 'android.arch.lifecycle:extensions:1.1.0'
  
  
      api 'androidx.core:core-ktx:0.2'
  
  
      api "com.google.dagger:dagger:$rootProject.dagger_version"
      kapt "com.google.dagger:dagger-compiler:$rootProject.dagger_version"
  
      api "android.arch.persistence.room:runtime:$rootProject.room_version"
      kapt "android.arch.persistence.room:compiler:$rootProject.room_version"
      testImplementation "android.arch.persistence.room:testing:$rootProject.room_version"
      api "android.arch.persistence.room:rxjava2:$rootProject.room_version"
      androidTestImplementation "android.arch.core:core-testing:$rootProject.room_version"
      testImplementation "android.arch.core:core-testing:$rootProject.room_version"
  
      api "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
      api "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
  
  
      api 'com.jakewharton.timber:timber:4.5.1'
  
      api "com.android.support:multidex:1.0.3"
  
      api "com.github.bumptech.glide:glide:$rootProject.glide_version"
      api "jp.wasabeef:glide-transformations:$rootProject.glide_transformation_version"
      api 'com.github.bumptech.glide:okhttp3-integration:1.5.0@aar'
  
      api "io.reactivex.rxjava2:rxandroid:$rootProject.rxAndroid_version"
      api "io.reactivex.rxjava2:rxjava:$rootProject.rxJava_version"
      api "com.google.code.gson:gson:$rootProject.gson_version"
  
      api("com.squareup.retrofit2:retrofit:$rootProject.retrofit_version") {
          // exclude Retrofit’s OkHttp peer-dependency module and define your own module import
          exclude module: 'okhttp'
      }
  
      api "com.squareup.okhttp3:okhttp:$rootProject.okhttp_version"
      api "com.squareup.okhttp3:logging-interceptor:$rootProject.okhttp_version"
      api "com.squareup.retrofit2:adapter-rxjava2:$rootProject.retrofit_version"
      api "com.squareup.retrofit2:converter-gson:$rootProject.retrofit_version"
  
      api 'com.jakewharton.threetenabp:threetenabp:1.0.5'
  
      api "com.google.firebase:firebase-invites:$rootProject.play_services_version"
      api "com.google.firebase:firebase-core:$rootProject.play_services_version"
      api "com.google.firebase:firebase-config:$rootProject.play_services_version"
      api "com.google.firebase:firebase-perf:$rootProject.play_services_version"
      api "com.google.firebase:firebase-auth:$rootProject.play_services_version"
      api "com.google.firebase:firebase-firestore:$rootProject.play_services_version"
  
  
  
      api("com.firebaseui:firebase-ui-auth:$rootProject.firebase_ui_version") {
          // exclude Retrofit’s OkHttp peer-dependency module and define your own module import
          exclude module: 'play-services-auth'
          exclude module: 'firebase-auth'
      }
  
      // Required only if Facebook login support is required
      api('com.facebook.android:facebook-android-sdk:4.31.0')
  
      api "com.google.android.gms:play-services-auth:$rootProject.play_services_version"
  
      // Required only if Twitter login support is required
      api("com.twitter.sdk.android:twitter-core:3.0.0@aar") { transitive = true }
  
      api 'com.jakewharton.rxbinding2:rxbinding-kotlin:2.0.0'
      api 'com.jakewharton.rxbinding2:rxbinding-support-v4-kotlin:2.0.0'
      api 'com.jakewharton.rxbinding2:rxbinding-appcompat-v7-kotlin:2.0.0'
      api 'com.jakewharton.rxbinding2:rxbinding-design-kotlin:2.0.0'
  
      api('com.crashlytics.sdk.android:crashlytics:2.9.1@aar') {
          transitive = true
      }
  }
  </code></pre>
  
  <p>I have also tried clean build and Rebuild project.</p>
  
  <p>Any idea how can i resolve this issue ?</p>