VT: Recorder gets payload type value from param

Removes hardcoded payload type in ARTPWriter.

A payload type will be assigned dynamically by an
upper layer as per SDP negotation.

Merged-in: I7c6f244c753c84a7954261b1c37292083ab5996a
Change-Id: I7c6f244c753c84a7954261b1c37292083ab5996a
Signed-off-by: Somraj Mani <som.mani@samsung.com>
Signed-off-by: Kim Sungyeon <sy85.kim@samsung.com>