Add missing pixel format constants, and mappings for
P010, packed variants of 420 and RGBA layouts to GStreamer
buffer formats. This fixes problems with android decoders
refusing to output raw video frames with decoders that
announce support for these common pixel formats and
only allowing the 'hardware surfaces output' path.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7743>
This allows the implementations to do custom logic behind the hood. For
example, when NDK implementation is added, the entrypoint can chooses to
statically initialize the NDK implementations or the JNI one.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4115>