ring-android/build.gradle

buildscript {
    repositories {
        jcenter()
        google()
        maven {
            url 'https://dl.bintray.com/poldz123/maven/'
        }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.0'
        classpath 'com.google.gms:google-services:3.1.1'
    }
}
allprojects {
    repositories {
        jcenter()
        google()
    }
}

task wrapper(type: Wrapper) {
    gradleVersion = '4.1' //version required
}