Gradle Build Flavor and Output Name Source: https://stackoverflow.com/questions/18332474/how-to-set-versionname-in-apk-filename-using-gradle

BuildVariant Flavor and Name

android {

    ...

    buildTypes {
        release {
            minifyEnabled true
            ...
        }
        debug {
            minifyEnabled false
        }
    }

    productFlavors {
        prod {
            applicationId "com.example.myproject"
            versionCode 3
            versionName "1.2.0"
        }
        dev {
            applicationId "com.example.myproject.dev"
            versionCode 15
            versionName "1.3.6"
        }
    }

    applicationVariants.all { variant ->
        variant.outputs.all { output ->
            def project = "myProject"
            def SEP = "_"
            def flavor = variant.productFlavors[0].name
            def buildType = variant.variantData.variantConfiguration.buildType.name
            def version = variant.versionName
            def date = new Date();
            def formattedDate = date.format('ddMMyy_HHmm')

            def newApkName = project + SEP + flavor + SEP + buildType + SEP + version + SEP + formattedDate + ".apk"

            outputFileName = new File(newApkName)
        }
    }
}

BuildVariant Name

android {
    applicationVariants.all { variant ->
        variant.outputs.each { output ->
            output.outputFile = new File(
                    output.outputFile.parent,
                    output.outputFile.name.replace(".apk", "-${variant.versionName}.apk"))
        }
    }
}