This change adds a new method onReadyToAcceptInputFrame to
GlTextureProcesssor.InputListener and changes maybeQueueInputFrame
to queueInputFrame, removing the boolean return value.
This avoids the re-trying in ChainingGlTextureProcessorListener
by allowing it to only feed frames from the producing to the consuming
GlTextureProcessor when there is capacity.
MediaPipeProcessor still needs re-trying when processing isn't 1:1.
PiperOrigin-RevId: 466626369
