question

You can try the following in your gradle config, I am not certain it works but I found it by Googling around (you may also need to set v3SigningEnabled false, not 100%):

    signingConfigs {
        release  {
            keyAlias "aliasHere"
            keyPassword "keyPassHere"
            storeFile file("pathToJksHere")
            storePassword "storePassHere"
            //Enable V1 signing
            v1SigningEnabled true
            v2SigningEnabled false
        }
    }

    buildTypes {
        release {
            minifyEnabled true
            //Use the signing configuration we just defined
            signingConfig signingConfigs.release
        }
    }