Make QuicStreamTest to check on OnDataAvailable() calls. Doing nothing when OnDataAvailable() is called seems a little dangerous. Also since we never read any data in the test. I think it's better to make the test stream level triggered so new data won't go unnoticed. gfe-relnote: n/a. test only. PiperOrigin-RevId: 276505442 Change-Id: I203db8cb3ed4d704ed29aafb3a531f3f5b54ee71