1. NDK integration is deprecated in the current plugin
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:compileDebugNdk'.
> Error: NDK integration is deprecated in the current plugin. Consider trying the new experimental plugin. For details, see http://tools.android.com/tech-docs/new-build-system/gradle-experimental. Set "$USE_DEPRECATED_NDK=true" in gradle.properties to continue using the current NDK integration.
2. Native C/C++ source code is found, but it seems that NDK option is not configured
Warning: Native C/C++ source code is found, but it seems that NDK option is not configured. Note that if you have an Android.mk, it is not used for compilation. The recommended workaround is to remove the default jni source code directory by adding:
jni.srcDirs = 
to build.gradle, manually compile the code with ndk-build, and then place the resulting shared object in src/main/jniLibs.