kmsrtpendpoint: Fix port configuration of audio rtp udpsink

Change-Id: I3333d5874535e1a7f0f32fcbb498454a46b7f868
kmsrtpendpoint: Do not stop processing sdp if offer or media is NULL

Change-Id: I5c1086a95f6a6e894e9d9e0242241a52407b1415
kmsrtpendpoint: Do not set qos property for udp sinks

Change-Id: I6d533b38641ff45e768efc87ea3a780792febcec