Gradle Invalid publication sample

build.grade (project instance)

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

buildscript {
    repositories {
        jcenter()
        maven { url 'https://maven.fabric.io/public' }
        google()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'
        classpath 'io.fabric.tools:gradle:1.24.1'
    }
}

allprojects {
    repositories {
        jcenter()
        maven { url 'https://maven.fabric.io/public' }
        flatDir {
            dirs 'libs-all'
        }
        google()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

build.gradle (Module)

apply plugin: 'com.android.library'
apply plugin: 'maven-publish'
apply plugin: 'maven'

android {
    compileSdkVersion 25
    buildToolsVersion '26.0.3'
    defaultConfig {
        minSdkVersion 23
        targetSdkVersion 25
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    lintOptions {
        abortOnError true
        disable 'LintError' 
    }
}

dependencies {
    androidTestImplementation('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    implementation 'com.android.support:appcompat-v7:25.4.0'
    implementation('com.crashlytics.sdk.android:crashlytics:2.6.8@aar') {
        transitive = true;
    }
    testImplementation 'junit:junit:4.12'
    testImplementation 'org.mockito:mockito-core:1.10.19'
    testImplementation "org.powermock:powermock-module-junit4:1.6.5"
    testImplementation "org.powermock:powermock-api-mockito:1.6.5"
}

task copyDependenciesToLib(type: Copy) {
    from configurations.findByName('compile')
    into "${project.rootDir}/module/libs-all"
}

preBuild.dependsOn(copyDependenciesToLib)

publishing {
    publications {
        AndroidDebug(MavenPublication) {
            groupId "${GROUP}"
            artifactId "${POM_ARTIFACT_ID}"
            version "${VERSION_NAME}"
            artifact "$buildDir/outputs/aar/module-debug.aar"
        }
        AndroidRelease(MavenPublication) {
            groupId "${GROUP}"
            artifactId "${POM_ARTIFACT_ID}"
            version "${VERSION_NAME}"
            artifact "$buildDir/outputs/aar/module-release.aar"
        }
    }
}

gradle-wrapper.properties

distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists
distributionUrl=https\://services.gradle.org/distributions/gradle-4.3.1-all.zip

gradle.properties

org.gradle.jvmargs=-Xmx1536m

POM_ARTIFACT_ID=generic-service
POM_PACKAGING=aar

VERSION_NAME=0.1-SNAPSHOT
GROUP=x.y.z