channel-display-gst: Add "byte-stream" as the stream format for h264

Adding the string "stream-format=byte-stream" to decoder capabilities
(dec_caps) for h264/h265 codecs stops Gstreamer from complaining
about missing stream format.

Cc: Frediano Ziglio <freddy77@gmail.com>
Cc: Dongwon Kim <dongwon.kim@intel.com>
Cc: Jin Chung Teng <jin.chung.teng@intel.com>
Cc: Hazwan Arif Mazlan <hazwan.arif.mazlan@intel.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Acked-by: Frediano Ziglio <freddy77@gmail.com>