Add stop threshold for afe proxy record.

As the stop threshold for afe proxy record is INT_MAX, the pcm will
never stop unless we manually call pcm_stop. In that case, we can't
detect the overrun state. Set the stop threshold as buffer size to stop
pcm when overrun. And then it will fall into XRUN and restart pcm.

Bug: 79121802
Test: Make phone call with usb-c adapter and headset.
Change-Id: I1f502b9017d6e2c811f625deb3bf659d81a60ca0