Activating USB Audio output for Manta

Change-Id: I03d5f53de60ba411721159c36e83f80b0ccd9835
diff --git a/audio_policy.conf b/audio_policy.conf
index 3cad223..4b65d9c 100644
--- a/audio_policy.conf
+++ b/audio_policy.conf
@@ -72,7 +72,7 @@
         devices AUDIO_DEVICE_OUT_USB_ACCESSORY
       }
       usb_device {
-        sampling_rates 44100
+        sampling_rates dynamic
         channel_masks AUDIO_CHANNEL_OUT_STEREO
         formats AUDIO_FORMAT_PCM_16_BIT
         devices AUDIO_DEVICE_OUT_USB_DEVICE