Second capture always switches to loopback

[tmthywynn8]

Using build a7fdb4e, it looks like when you stop a capture and start a new one within the same session, i.e., don't close an reopen ap, it starts recording system audio, i.e., loopback regardless of process chosen.

Steps to reproduce:

1. Open Audio Capture.
2. Check the following options:
   • Monitor audio
   • Monitor only (no recording)
3. In the list of Available processes, check only your screen reader audio.
4. Press Start Capture, press Stop Capture, and press Start Capture again.
   • Expected: The second capture's output should be identical to the first.
   • Actual: Feedback is heard from your screen reader and any audio playing. If you can't hear the UI well enough to stop, press Alt+S.