Add local .aar file

1. basic build.gradle directory using flatDir

repositories {
    mavenCentral()
    flatDir {
        dirs 'libs'
    }
}

1. app/build.gradle

//way1:
dependencies {
   compile 'com.kevinpelgrims.library:library:1.0.0@aar'
}

//or way2: store the .aar file in libs
dependencies {
    compile(name:'libraryfilename', ext:'aar')
}