Actual frame size and bitrate is all 0 when using SVC sample encoder
with sl = 1 because the stats are set in parse_superframe_index which
will not caculate properly when sl = 1 since there is no superframe.
Use pkt->data.frame.sz instead when sl = 1.
Change-Id: I93f5e98a4c779e32b007e1564ba5396af9e34ad6