Transformer.experimentalSetMaxFramesInEncoder controls max number
of frames in encoder.
VideoFrameProcessor now allows delayed releasing of frames to Surface,
while still using the original presentation time.
VideoSampleExporter can now configure video graphs to not render frames
automatically to output surface.
VideoSampleExporter.VideoGraphWrapper tracks how many frames are ready
to be rendered to Surface, and how many frames are already in-use by encoder.
PiperOrigin-RevId: 658429969
ddc86686b7