use std::shared_ptr instead of pointer of instance

use std::shared_ptr instead of pointer of instance

using std::shared_ptr to handle heap memory space

**Self evaluation:**
1. Build test:	 [X]Passed [ ]Failed [ ]Skipped
2. Run test:	 [X]Passed [ ]Failed [ ]Skipped

Signed-off-by: jijoong.moon <jijoong.moon@samsung.com>