title: How to build a part of Android AOSP?
body: <p>I am trying to build my own libs and apps in external directory of the AOSP, but the problem is i have to run make each time and the make will compile/build whole the android. 
  In my external apps folder i have Android.mk file, but i cannot build it using ndk-build, it will look for JNI folder and NDK_BUILD_PATH, so the question is:</p>
  
  <p>How can i build it without rebuilding whole AOSP?</p>