gradle: package *.jar into aar

aar-deps.gradle

project.projectsEvaluated {
    def isAndroidLibraryProject = project.plugins.hasPlugin('com.android.library')
    if(isAndroidLibraryProject) {
        task copyDeps(type:Copy) {
            from configurations.compile
            into "./build/intermediates/bundles/release/libs/"
        }
        preBuild.dependsOn copyDeps

        task copyDebugDeps(type:Copy) {
            from configurations.compile
            into "./build/intermediates/bundles/debug/libs/"
        }
        preDebugBuild.dependsOn copyDebugDeps
    }
}

build.gradle

apply plugin: 'com.android.library'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.1"

    defaultConfig {
        minSdkVersion 18
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.squareup.okhttp3:okhttp:3.0.1'
    compile 'com.mcxiaoke.volley:library:1.0.19'
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.1.0'
}

gradle.projectsEvaluated {

    ["", "Debug"].each { taskId ->
        task "copy${taskId}Deps"(type:Copy) {
            from configurations.compile
            def target = "copyDeps" == name ? "release" : "debug"
            def dir = "./build/intermediates/bundles/$target/libs/"
            into dir
        }
        tasks["pre${taskId}Build"].dependsOn "copy${taskId}Deps"
    }
}