mux: mp4: use hev1 as sample entry for HEVC
mux: mp4: use hev1 as sample entry for HEVC

hvc1 is reserved for streams with VCL only

xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc