codec_flow: set codec recording to NONE after capturing audio

Codec should stop recording from either LINEIN or MIC when user calls
StopCapturingAudio.

BUG=None
TEST=run audio_AudioBasicHeadphone test. User ./fpga report on chameleon
to check codec is not recording from LineIn.

Change-Id: Ib8d081be95cb6ab45869bdc70ff26d1ba026969f
Reviewed-on: https://chromium-review.googlesource.com/245301
Reviewed-by: Hung-ying Tyan <tyanh@chromium.org>
Commit-Queue: Cheng-Yi Chiang <cychiang@chromium.org>
Tested-by: Cheng-Yi Chiang <cychiang@chromium.org>
diff --git a/chameleond/utils/codec_flow.py b/chameleond/utils/codec_flow.py
index 491e65f..b19a675 100644
--- a/chameleond/utils/codec_flow.py
+++ b/chameleond/utils/codec_flow.py
@@ -153,6 +153,7 @@
       AudioCaptureManagerError: If there is no captured data.
     """
     return_value = self._audio_capture_manager.StopCapturingAudio()
+    self._audio_codec.SelectInput(codec.CodecInput.NONE)
     self.ResetRoute()
     return return_value