app.build.gradle

// The app level

apply plugin: 'com.android.application'

android {
    def globalConfiguration = rootProject.extensions.getByName("ext")

    compileSdkVersion globalConfiguration["androidCompileSdkVersion"]
    buildToolsVersion globalConfiguration["androidBuildToolsVersion"]

    defaultConfig {
        applicationId "com.androidessence.myapplication"
        minSdkVersion globalConfiguration["androidMinSdkVersion"]
        targetSdkVersion globalConfiguration["androidTargetSdkVersion"]
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile "com.android.support:appcompat-v7:${supportLibraryVersion}"
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    testCompile 'junit:junit:4.12'
}

project.build.gradle

// The project level

// 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:2.3.1'

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

allprojects {
    repositories {
        jcenter()
    }

    ext {
        //Android
        androidBuildToolsVersion = "25.0.2"
        androidMinSdkVersion = 16
        androidTargetSdkVersion = 25
        androidCompileSdkVersion = 25

        //Libraries
        supportLibraryVersion = "25.3.1"
    }
}

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