sample upload pom file

local.properties

url="/helloaar/"
username=USERNAME
password=PASSWORD

upload.gradle

//upload.gradle: same folder with build.gradle of library module
apply plugin: 'maven-publish'

afterEvaluate {
   publishing {
       publications {
           release(MavenPublication) {
               groupId libraryGroupId
               artifactId libraryArtifactId
               version libraryVersion
               from components.release
           }
       }
       repositories {
           maven {
               url = "/helloaar/" // local folder
               credentials {
                   username "${username}"
                   password "${password}"
               }
           }
       }
   }
}