CCodec: fix input surface throttling

There were no throttling in place for video encoders set up with
input surfaces. Throttle based on the number of output buffers
notified to the client.

Bug: 310807188
Test: atest android.hardware.camera2.cts.RecordingTest
Test: atest android.mediav2.cts.CodecEncoderSurfaceTest
Change-Id: Ifec1d16ed25f8100ae1f1eb06a490c955c0c4961