Add your android library to the sonatype (maven central)

build.gradle

Define these lines to the library gradle file:

project.group = "io.github.rezaiyan"
project.archivesBaseName = "LevelProgressBar"
project.version = "1.0.0"
apply from: '../publish.gradle'

global_gradle.properties

# home/.gradle/gradle.properties

nexusUsername=user
nexusPassword=pass

local_gradle.properties

# projectDir/gradle.properties

GROUP=io.github.rezaiyan
POM_ARTIFACT_ID=levelprogressbar
POM_PACKAGING=aar

VERSION_NAME=1.0.3
VERSION_CODE=1.0.3

POM_NAME=LevelProgressBar
POM_DESCRIPTION=An custom progressbar for android.
POM_INCEPTION_YEAR=2020
POM_URL=https://github.com/rezaiyan/LevelProgressBar/

POM_LICENCE_NAME=The Apache Software License, Version 2.0
POM_LICENCE_URL=https://www.apache.org/licenses/LICENSE-2.0.txt
POM_LICENCE_DIST=repo

POM_SCM_URL=https://github.com/rezaiyan/LevelProgressBar/
POM_SCM_CONNECTION=scm:git:git://github.com/rezaiyan/LevelProgressBar.git
POM_SCM_DEV_CONNECTION=scm:git:ssh://git@github.com/rezaiyan/LevelProgressBar.git

POM_DEVELOPER_ID=rezaiyan
POM_DEVELOPER_NAME=Ali Rezaiyan
POM_DEVELOPER_URL=https://github.com/rezaiyan/
RELEASE_REPOSITORY_URL=https://s01.oss.sonatype.org/service/local/staging/deploy/maven2/
SNAPSHOT_REPOSITORY_URL=https://s01.oss.sonatype.org/content/repositories/snapshots/

publish.gradle

apply plugin: 'maven'
apply plugin: 'signing'

def sonatypeRepositoryUrl
if (isReleaseBuild()) {
  println 'RELEASE BUILD'
  sonatypeRepositoryUrl = hasProperty('RELEASE_REPOSITORY_URL') ? RELEASE_REPOSITORY_URL
      : "https://s01.oss.sonatype.org/service/local/staging/deploy/maven2/"
} else {
  println 'DEBUG BUILD'
  sonatypeRepositoryUrl = hasProperty('SNAPSHOT_REPOSITORY_URL') ? SNAPSHOT_REPOSITORY_URL
      : "https://s01.oss.sonatype.org/content/repositories/snapshots/"
}

def getRepositoryUsername() {
  return hasProperty('nexusUsername') ? nexusUsername : ""
}

def getRepositoryPassword() {
  return hasProperty('nexusPassword') ? nexusPassword : ""
}

afterEvaluate { project ->
  uploadArchives {
    repositories {
      mavenDeployer {
        beforeDeployment { MavenDeployment deployment -> signing.signPom(deployment) }

        pom.artifactId = POM_ARTIFACT_ID

        repository(url: sonatypeRepositoryUrl) {
          authentication(userName: getRepositoryUsername(), password: getRepositoryPassword())
        }

        pom.project {
          name POM_NAME
          packaging POM_PACKAGING
          description POM_DESCRIPTION
          url POM_URL

          scm {
            url POM_SCM_URL
            connection POM_SCM_CONNECTION
            developerConnection POM_SCM_DEV_CONNECTION
          }

          licenses {
            license {
              name POM_LICENCE_NAME
              url POM_LICENCE_URL
              distribution POM_LICENCE_DIST
            }
          }

          developers {
            developer {
              id POM_DEVELOPER_ID
              name POM_DEVELOPER_NAME
            }
          }
        }
      }
    }
  }

  signing {
    required { isReleaseBuild() && gradle.taskGraph.hasTask("uploadArchives") }
    sign configurations.archives
  }

  task androidJavadocs(type: Javadoc) {
    source = android.sourceSets.main.java.sourceFiles
  }

  task androidJavadocsJar(type: Jar) {
    classifier = 'javadoc'
    //basename = artifact_id
    from androidJavadocs.destinationDir
  }

  task androidSourcesJar(type: Jar) {
    classifier = 'sources'
    //basename = artifact_id
    from android.sourceSets.main.java.sourceFiles
  }

  artifacts {
    //archives packageReleaseJar
    archives androidSourcesJar
    archives androidJavadocsJar
  }
}
def isReleaseBuild() {
  return version.contains("SNAPSHOT") == false
}