title: Android Studio 2.2 doesn't package third party library to apk
body: <p>I use Android Studio 2.2's <code>cmake</code> to build native code, in the native code I invoked the ffmpeg api, so the ffmpeg library should be packaged. My <code>CMakelists.txt</code> is as below:</p>
  
  <pre><code>cmake_minimum_required(VERSION 3.4.1)
  include_directories(libs/arm/include)
  link_directories(libs/arm/lib/)
  
  add_library( # Sets the name of the library.
               native-lib
  
               # Sets the library as a shared library.
               SHARED
  
               # Provides a relative path to your source file(s).
               # Associated headers in the same location as their source
               # file are automatically included.
               src/main/cpp/native-lib.cpp )
  
  
  find_library( # Sets the name of the path variable.
                log-lib
  
                # Specifies the name of the NDK library that
                # you want CMake to locate.
                log )
  
  target_link_libraries( # Specifies the target library.
                         native-lib
  
                         # Links the target library to the log library
                         # included in the NDK.
                         ${log-lib} )
  add_library(avcodec-57 SHARED IMPORTED)
  set_target_properties(avcodec-57 PROPERTIES IMPORTED_LOCATION C:/Users/tony/Desktop/MyApplication/app/libs/arm/lib/libavcodec-57.so)
  target_link_libraries(native-lib avcodec-57)
  target_link_libraries(native-lib avformat-57)
  
  target_link_libraries(native-lib avutil-55)
  target_link_libraries(native-lib avfilter-6)
  </code></pre>
  
  <p>In such case, I can make project successfully, but when I install the apk to emulator and run, it failed and show that "libavcodec-57.so" isn't found.
  Then I use tool (analyze apk) to check the apk, found that the ffmpeg library isn't packaged.</p>