title: androidJacocoAnt configuration no longer found with Android Gradle plugin 3.1.0
body: <p>After updating to Android Gradle plugin 3.1.0 (from 3.0.1) my JaCoCo unit test coverage configuration started producing errors in Gradle config phase:</p>
  
  <pre><code>&gt; Configuration with name 'androidJacocoAnt' not found.
  </code></pre>
  
  <p>Project-level build.gradle:</p>
  
  <pre><code>dependencies {
      classpath 'com.android.tools.build:gradle:3.1.0'
      classpath "org.jacoco:org.jacoco.core:0.8.1"
  }
  </code></pre>
  
  <p>Module-level build.gradle:</p>
  
  <pre><code>apply plugin: 'jacoco'
  
  ...
  
  android {
      buildTypes {
          debug {
              testCoverageEnabled true
          }
      }
  
      ...
  }
  
  task jacocoTestReport(type: JacocoReport) {
      dependsOn 'createDebugCoverageReport'
      dependsOn 'testDebugUnitTest'
  
      reports {
          xml.enabled = true
          html.enabled = true
          csv.enabled = false
      }
  
      jacocoClasspath = configurations['androidJacocoAnt']
  
      def fileFilter = [
              '**/R.class',
              '**/R$*.class',
              '**/BuildConfig.*',
              '**/Manifest*.*',
              '**/*Test*.*',
              'android/**/*.*'
      ]
  
      def debugTree = fileTree(dir: "${buildDir}/intermediates/classes/debug", excludes: fileFilter)
      def mainSrc = "${project.projectDir}/src/main/java"
      print("${project.projectDir}/src/main/java")
  
      sourceDirectories = files([mainSrc])
      classDirectories = files([debugTree])
      executionData = fileTree(dir: "$buildDir", includes: [
              "jacoco/testDebugUnitTest.exec",
              "outputs/code-coverage/connected/*coverage.ec"
      ])
  }
  </code></pre>