get_apk_info.gradle

import groovy.json.JsonOutput
import com.google.common.io.Files

android.applicationVariants.all { variant ->
    variant.assemble.doLast {
        variant.outputs.each { output ->
            def apkInfo = [
                    apk: output.outputFile.absolutePath,
                    versionCode: variant.versionCode,
                    versionName: variant.versionName
            ]
            println apkInfo

            def outFile = new File(project.getRootDir(), "${variant.name}.json")
            Files.createParentDirs(outFile)
            outFile.write(JsonOutput.toJson(apkInfo))
        }
    }
}