[Cin] vp9 high bit depth, vp9 lossless profile

so I played around with vp9 enciding a bit more. apoarently there is vp9 lossless mode, and additionally libvpx can support high bit depth if configured so. I also tried to remove (currently unused?) libavdevice build from ffmpeg, and fix termux breakage (libandroid-shmem lib was missing) try attached patches and check if vdpau/vaapi still works?