native camera2 android ndk

Hello Camera2 ============= Hello Camera2 is an Android Camera2 sample that plays preview. It controls camera devices by NDK camera2 APIs which becomes one of [public libraries](http://android-developers.blogspot.kr/2016/06/improving-stability-with-private-cc.html) in Android N. Pre-requisites -------------- - Android Studio 2.1+ with [NDK](https://developer.android.com/ndk/) (>=r12) bundle. Screenshots ----------- A small extra view is toggled when a screen is touched.  Known Bugs ---------- * When extra surface view is changed, App is crashed. (e.g when switching portrait to landscape mode, vice versa)