Gradle task to archive APKs once built through android studio by running ./gradlew deployApks

deployApks.groovy

task deployApks(type:Copy) {
    description = "Copies APKs and Proguard mappings to the deploy directory"
    def appName = "posture";
    def versionDir = android.defaultConfig.versionName+"_"+android.defaultConfig.versionCode;

    println("Copies APK and Proguard to " + versionDir)

    from 'build/outputs/mapping/release/'
    include '**/mapping.txt'
    into '../.admin/deploy/' + versionDir
    rename ('mapping.txt', "${versionDir}-mapping.txt")

    from ('.') {
        exclude '**/build', '**/src'
    }

    include '*.apk'
    into '../.admin/deploy/' + versionDir
    rename ('app-release.apk', "${appName}-${versionDir}.apk")
}

Thanks to @Manoj.Madanmohan for letting me know this can be extended for every build by applying this additional code

applicationVariants.all { variant ->
       variant.outputs.each { output ->
              variant.assemble.doLast {
         //your task here
             }
          }
 }