fluro/example/android/app/build.gradle

// flutter
def localProperties = new Properties()
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
    localPropertiesFile.withInputStream { stream ->
        localProperties.load(stream)
    }
}

def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
    throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}

apply plugin: 'com.android.application'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"

flutter {
    source '../..'
}

// build versioning
def currentVersionCode() {
    def propsFile = file('versions.properties')
    def props = new Properties()
    props.load(new FileInputStream(propsFile))
    return props['build.versionCode'].toInteger()
}

def incrementVersionCode() {
    def propsFile = file('versions.properties')
    def props = new Properties()
    props.load(new FileInputStream(propsFile))
    def currentCode = props['build.versionCode'].toInteger()
    def nextCode = currentCode + 1
    props['build.versionCode'] = nextCode.toString()
    props.store(propsFile.newWriter(), null)
    return nextCode
}

// increments build version code on release builds
task('incrementVersionCode') << {
    incrementVersionCode()
}

tasks.whenTaskAdded { task ->
    if (task.name == 'assembleRelease') {
        task.dependsOn 'incrementVersionCode'
    }
}

buildscript {
    // application variables
    ext.app_ver_name = "1.0"

    // google version codes
    ext.build_tools_ver = '25.0.3'
    ext.support_lib_ver = '25.3.1'
    ext.google_play_ver = '10.2.4'
    ext.constraint_layout_ver = '1.0.2'
}

android {
    compileSdkVersion 25
    buildToolsVersion "$build_tools_ver"

    defaultConfig {
        minSdkVersion 19
        targetSdkVersion 25
        applicationId "com.goposse.routersample"
        versionCode currentVersionCode()
        versionName "$app_ver_name"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    lintOptions {
        disable 'InvalidPackage'
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    buildTypes {
        release {
            // TODO: Add your own signing config for the release build.
            // Signing with the debug keys for now, so `flutter run --release` works.
            signingConfig signingConfigs.debug
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])

    // google
    compile "com.android.support:appcompat-v7:$support_lib_ver"
    compile "com.android.support:support-v13:$support_lib_ver"
    compile "com.android.support:support-v4:$support_lib_ver"

    // testing
    androidTestCompile "com.android.support:support-annotations:$support_lib_ver"
    androidTestCompile 'com.android.support.test:runner:0.5'
    androidTestCompile 'com.android.support.test:rules:0.5'
}