add maven repository to build.gradle

You will need to define the repository outside of buildscript. The buildscript configuration block only sets up the repositories and dependencies for the classpath of your build script but not your application.

After

apply plugin: 'com.android.application'

You should add this:

  repositories {
        mavenCentral()
        maven {
            url "https://repository-achartengine.forge.cloudbees.com/snapshot/"
        }
    }

@Benjamin explained the reason.

If you have a maven with authentication you can use:

repositories {
            mavenCentral()
            maven {
               credentials {
                   username xxx
                   password xxx
               }
               url    'http://mymaven/xxxx/repositories/releases/'
            }
}

It is important the order.