class AndroidModulePlugin : Plugin<Project> {
    override fun apply(target: Project) {
        with(target) {

            // ...

            tasks.register("reportMerge", ReportMergeTask::class.java) {
                output.set(rootProject.layout.buildDirectory.file("reports/detekt/merge.xml"))
            }

            tasks.withType<Detekt>().configureEach {
                buildUponDefaultConfig = true
                reports {
                    xml.required.set(true)
                }
                finalizedBy("reportMerge")
            }

            tasks.withType<ReportMergeTask> {
                input.from(project.layout.buildDirectory.file("reports/detekt/detekt.xml"))
            }

            // ...

        }
    }
}