Meteor offline build (android Offline Gradle error)

i need to build my App without any internet connection. I built this App with internet connection aldy.

But, after convert to offline-mode, some errors showed like below >
***** “compileSdkVersion is not specified.

If I connect internet again, it works fine(build). I spent so many days with this problem. And I figured that
I need to set Android build setting --> offline gradle mode

I know how to set this offline mode at Android-Studio tool.
( Android-Studio > Preferences > Gradle > offline mode check )

But I hav no idea how to make this same circumstances with build.gradle file editing.

buildscript {
repositories {

dependencies {
          classpath ''


allprojects {
repositories {
… etc

So, how can make this environment with editing ‘build.gradle’ file ???

plz help me…