title: Include aar in android Makefile project
body: <p>I'm trying to build an Android app through makefile (the app works perfectly when build by Android Studio).</p>
  
  <p>I'm having problems with an .aar module that is used. the make completes successfully, but the .apk size is ridiculously small (500kb instead of 80mb).
  The .aar has multiple .so files in ./libs, as well as ./assets, but both seem not to be included.</p>
  
  <p>Android.mk:</p>
  
  <pre><code>LOCAL_SHARED_LIBRARIES := libnativelib
  LOCAL_STATIC_JAVA_LIBRARIES:= aarmodulename
  ...
  ...
  include $(BUILD_PACKAGE)
  include $(CLEAR_VARS)
  LOCAL_PREBUILT_STATIC_JAVA_LIBRARIES:=aarmodulename:libs/aarmodulename.aar
  include $(BUILD_MULTI_PREBUILT)
  </code></pre>
  
  <p>I've also tried forcing the .so files to be packaged, but I dpn't even know if this is the proper way to do so:</p>
  
  <pre><code>include $(CLEAR_VARS)
  LOCAL_MODULE := libnativelib
  LOCAL_SRC_FILES := libs/so/libnativelib.so
  LOCAL_MODULE_TAGS := optional
  LOCAL_MODULE_SUFFIX := .so 
  LOCAL_MODULE_CLASS := SHARED_LIBRARIES 
  include $(BUILD_PREBUILT)
  </code></pre>
  
  <p>Why don't the *.so files and the aar's assets get packaged? How do I fix it?</p>