Use a specific minSdkVersion only in a Debug mode

How can I use a specific minSdkVersion only in a debug mode?I want to use the minSdkVersion 21 for debug mode, but minSdkVersion 15 for the release. I don't wanna use flavors for this because will give troubles.

I think the could be like this (but don't work):

defaultConfig {        applicationId "blacktoad.com.flapprototipo"        minSdkVersion 15        debug{            minSdkVersion 21        }        targetSdkVersion 23        versionCode 42        versionName "1.72"        multiDexEnabled true    }