goldfish-opengl: One virtio-gpu instance per API instance

Previously, there was an auxiliary rendernode in addition to the
one used by the stream.  This removes the auxiliary rendernode,
and creates one virtgpu instance per process API instance.

BUG=202552093
TEST=run gfxstream, deqp-vk in Linux guest

Change-Id: I08348174af0e4207358c56babb509a88ce12ec8c
4 files changed