【错误记录】Gradle 配置 productFlavors 报错 ( All flavors must now belong to a named flavor dimension. )

// 定义不同的开发和产品风格
    productFlavors {
        // 开发风格
        dev {
            // 开发时使用 minSDKVersion = 21 允许 Android Gradle 插件
            // 为每个 Module 模块产生一个 APK 安装包 , 可以在 Android Lollipop 系统上进行测试
            // 无需进行耗时的 dex 合并过程
            minSdkVersion 21
        }
        // 产品风格
        prod {
            // 应用实际的最小 SDK
            minSdkVersion 14
        }
    }

FAILURE: Build failed with an exception.
* What went wrong:
A problem occurred configuring project ':app'.
> All flavors must now belong to a named flavor dimension. Learn more at https://d.android.com/r/tools/flavorDimensions-missing-error-message.html
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org
BUILD FAILED in 198ms

android {
    defaultConfig {
        // 维度版本号
        flavorDimensions "1.0"
    }
}