[steam/f29] (5 commits) ...Fix Nvidia Shield Portable streaming with SteamLink

Summary of changes: 8a7dcc5... Drop vulkan on el7 for now (*) 4d637f5... Update changelog (*) c9fd3d6... don't override NOFILE systemd limits on F30+ (*) 2fb7be6... fix macro condition check for vulkan libs (*) bd181cb... Fix Nvidia Shield Portable streaming with SteamLink (*) (*) This commit already existed in another branch; no separate mail sent