ndk-build by self
cd jni
ndk-build
cd app/src/main
javah -d jni -classpath java com.hpchen.testndk02.app.MainActivity
sourceSets.main.jni.srcDirs = [] //disable automatic ndk-build call
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := MyLib
LOCAL_SRC_FILES := main.c
include $(BUILD_SHARED_LIBRARY)