Solution are founded. Flavors should be declared before using it, so right build gradle is:
android {
productFlavors {
google {}
secure {
packageName "com.some_secure.package"
}
}
dependencies {
secureCompile project(':relatedProjects:gd')
}
compileSdkVersion "Google Inc.:Google APIs:19"
buildToolsVersion "18.1.1"
}