Gradle task that downloads a signing config from a remote server

app_build.gradle

def execDownloadSigningInfo(ProductFlavor flavor) {
    task z {
        download {
            src "$url"

            dest {
                return rootProject.file("../file")
            }
            onlyIfNewer true
        }
    }

    task x(dependsOn: z) {
        rootProject.ext.generateSigningConfig(android.signingConfigs, flavor)
    }
}

build.gradle

 buildscript {
     [...]
     dependencies {
         [...]
         classpath 'de.undercouch:gradle-download-task:3.4.3'
     }
 }