realm-js/examples/ReactExample/android/build.gradle

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

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.3.1'

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

allprojects {
    repositories {
        mavenLocal()
        jcenter()
        jcenter {
            url "http://dl.bintray.com/mkonicek/maven"
        }
        maven { url "https://jitpack.io" }
    }
}