Add tf_classify reference application (#3642)

Add tf_classify reference application (#3642)

* Add tf_classify reference application

This patch creates an `example` directory
The tf_classify application is based on TendofFlow Android Camera Demo.

Signed-off-by: Jiyoung Yun <jy910.yun@samsung.com>
* Change application name and move the location

Use tflite_classify instead of tf_classify
Move application under contrib directory
Do not support to download files

Signed-off-by: Jiyoung Yun <jy910.yun@samsung.com>
* Add const keyword and remove unnecessary library link

Signed-off-by: Jiyoung Yun <jy910.yun@samsung.com>
* Use std::vector instead of c-style array

Signed-off-by: Jiyoung Yun <jy910.yun@samsung.com>
* Use OpenCV C++ apis

Signed-off-by: Jiyoung Yun <jy910.yun@samsung.com>