title: getting red line in files after upgrading to gradle 4.4 and gradle build tools version 3.1.2
body: <p>The Android studio ask me to update the gradle version to 4.4 and gradle build tool version to 3.1.2.
  After the update, The whole android studio shows red lines in file, when I hover my cursor on these error it says &quot;cannot resolve symbol&quot; but compiles with no error i.e., build is successful.<a href="https://i.stack.imgur.com/Eyehj.png" rel="nofollow noreferrer">Click here to see red lines in java files</a></p>
  <p>and Here are the gradle app and project files.</p>
  <pre><code>//Build.gradle(project)
  //Top-level build file where you can add configuration options common to all sub-projects/modules.
  
  buildscript {
      repositories {
          maven {
              url 'https://maven.fabric.io/public'
          }
  
          jcenter()
          maven {
  
              url 'https://maven.google.com/'
              name 'Google'
          }
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:3.1.2'
          classpath 'com.google.gms:google-services:3.2.0'
          classpath 'io.fabric.tools:gradle:1.25.1'
          // NOTE: Do not place your application dependencies here; they belong
          // in the individual module build.gradle files
      }
  }
  
  allprojects {
      repositories {
          maven {
              url 'https://maven.google.com/'
          }
          jcenter()
      }
  }
  
  task clean(type: Delete) {
      delete rootProject.buildDir
  }
  </code></pre>
  <p>and</p>
  <pre><code>//build.gradle(module:app)
  apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 27
      buildToolsVersion '27.0.3'
      defaultConfig {
          applicationId &quot;com.developers.paras.droidwatch&quot;
          minSdkVersion 19
          targetSdkVersion 27
          versionCode 9
          versionName &quot;9.0&quot;
          multiDexEnabled true
          testInstrumentationRunner &quot;android.support.test.runner.AndroidJUnitRunner&quot;
      }
      buildTypes {
          release {
              minifyEnabled true
              shrinkResources true
              android.defaultConfig.vectorDrawables.useSupportLibrary = true
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
      androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
          exclude group: 'com.android.support', module: 'support-annotations'
      })
      compile 'com.android.support:appcompat-v7:27.1.1'
      compile 'com.android.support:customtabs:27.1.1'
      compile 'com.android.support.constraint:constraint-layout:1.1.0'
      compile 'com.android.support:design:27.1.1'
      compile 'com.android.support:support-v4:27.1.1'
      compile 'com.google.android.gms:play-services-ads:15.0.1'
      compile 'com.google.firebase:firebase-core:15.0.2'
      compile 'com.crashlytics.sdk.android:crashlytics:2.9.2'
      testCompile 'junit:junit:4.12'
  }
  apply plugin: 'com.google.gms.google-services'
  apply plugin: 'io.fabric'
  </code></pre>
  <p>Things I have already tried.</p>
  <ol>
  <li>Clean and Rebuild.</li>
  <li>Invalidate Cache and Restart.</li>
  <li>Updating gradle version to 4.9.</li>
  <li>Setting local gradle for the project.</li>
  </ol>
  <p>See my gradle logs here <a href="https://drive.google.com/open?id=18bFZdkWX4AFPfpmfjvN1t80WpVRpiHWs" rel="nofollow noreferrer">https://drive.google.com/open?id=18bFZdkWX4AFPfpmfjvN1t80WpVRpiHWs</a></p>
  <p>See even release build is generated after these errors. <a href="https://i.stack.imgur.com/Vi1Oo.png" rel="nofollow noreferrer">Release apk generated</a></p>
  <p><strong>Update</strong> : Recently after Reinstalling Studio, I've created a new project and everything works fine. No errors for &quot;cannot resolve symbol&quot;.</p>