Gradle ignores source setting for native part in flavor

I have next pat in build.gradle :
nativetest {
jni {
source {
srcDir(NATIVE_DIR + ‘/GTest’) //gragle ignore this line
srcDir(GOOGLETEST_DIR + ‘/src’) //gragle ignore this line
}
java {
source {
srcDir ‘src/dev/java’ //gradle accepts this line
}
}
}
}

but gradle doesn’t add directories from jni part to compile (only java part is accepted and and to compile)
What is problem? How can I add source directories for specific flavor for native part to compile?
Thanks