Plugin [id: 'com.android.application'] was not found in any of the following sources: code example

Example: Plugin with id 'com.android.application' not found.

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.xx.y'
    }
}

allprojects {
    repositories {
        mavenCentral()
    }
}