audio: add 24000 Hz capture sampling rate

Bug 6615379.

Change-Id: I5ef2cc168bbe26b40c49e602d6345c1b64c2b1b0
diff --git a/audio/audio_policy.conf b/audio/audio_policy.conf
index 3a41ec1..1012c26 100644
--- a/audio/audio_policy.conf
+++ b/audio/audio_policy.conf
@@ -46,7 +46,7 @@
     }
     inputs {
       primary {
-        sampling_rates 8000|11025|16000|22050|32000|44100|48000
+        sampling_rates 8000|11025|16000|22050|24000|32000|44100|48000
         channel_masks AUDIO_CHANNEL_IN_MONO|AUDIO_CHANNEL_IN_STEREO
         formats AUDIO_FORMAT_PCM_16_BIT
         devices AUDIO_DEVICE_IN_BUILTIN_MIC|AUDIO_DEVICE_IN_BLUETOOTH_SCO_HEADSET|AUDIO_DEVICE_IN_WIRED_HEADSET|AUDIO_DEVICE_IN_BACK_MIC