title: gradle.lang.MissingPropertyException
body: <p>I am trying to open my project in android studio SDK but, this <strong>groovy.lang.MissingPropertyException: Could not get unknown property 'KEY_ALIAS' for project ':app' of type org.gradle.api.Project.</strong> is ocuring. I don't know how to correct it. Please help.
  I am using <strong>Android Studio 3.6.2</strong>
  Here is my <code>build/gradle</code> file -</p>
  
  <p>buildscript {</p>
  
  <pre><code>repositories {
      google()
      jcenter()
      maven {
          url 'https://maven.fabric.io/public'
      }
  }
  dependencies {
      classpath 'com.android.tools.build:gradle:3.1.3'
      classpath 'com.google.gms:google-services:4.0.1'
      classpath 'io.fabric.tools:gradle:1.25.4'
  
  
      // NOTE: Do not place your application dependencies here; they belong
      // in the individual module build.gradle files
  }
  }
  
  allprojects {
  repositories {
      google()
      jcenter()
  }
  }
  
  ext {
  supportLibraryVersion = '27.1.1'
  constraintLayoutVersion = '1.1.2'
  lifecycleVersion = "1.1.1"
  butterKnifeVersion = '8.8.1'
  glideVersion = '4.7.1'
  timberVersion = '4.7.0'
  gsonVersion = '2.8.2'
  firebaseVersion = '16.0.1'
  crashlyticsVersion = '2.9.4'
    }
  
   task clean(type: Delete) {
  delete rootProject.buildDir
  }
  </code></pre>