override gradle project repositories in init script

init.gradle

projectsEvaluated {
  rootProject.allprojects {
    buildscript.repositories {
      resolverNames = []
      mavenRepo name: 'plugins-repo', urls: 'http://repository.example.org/plugins'
    }
    repositories {
      resolverNames = []
      mavenRepo name: 'libs-repo', urls: 'http://repository.example.org/libs'
    }
  }
}