build.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    ext.kotlin_version = '1.2.71'
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.1'
       // classpath 'com.netflix.nebula:gradle-aggregate-javadocs-plugin:2.2.+'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"


        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}
//apply plugin: "nebula-aggregate-javadocs"
task clean(type: Delete) {
    delete rootProject.buildDir
}

task javadoc(type: Javadoc) {
    source subprojects.collect { project ->
        project.sourceSets.main.allJava
    }
    destinationDir = new File(buildDir, 'javadoc')
    // Configure the classpath
    classpath = files(subprojects.collect { project ->
        project.sourceSets.main.compileClasspath
    })
}