react-native-config/android/build.gradle

buildscript {
    repositories {
        jcenter()
        google()        
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.4'
    }
}

apply plugin: 'com.android.library'

def safeExtGet(prop, fallback) {
    rootProject.ext.has(prop) ? rootProject.ext.get(prop) : fallback
}

android {
    compileSdkVersion safeExtGet("compileSdkVersion", 26)
    buildToolsVersion safeExtGet("buildToolsVersion", "27.0.3")

    defaultConfig {
        minSdkVersion safeExtGet("minSdkVersion", 16)
        targetSdkVersion safeExtGet("targetSdkVersion", 26)
        versionCode 1
        versionName "1.0"
    }
    lintOptions {
        abortOnError false
    }
}

repositories {
    mavenCentral()
}

dependencies {
    implementation "com.facebook.react:react-native:${safeExtGet("reactNative", "+")}" // from node_modules
}