hal: Use echo ref snd device only for echo ref use cases
- checks if uc_id is for echo ref use case
- ensures auto-only use of echo ref snd device

Change-Id: I90db4ff88bebc967d59a680c0c2629fdc9fb2daf
diff --git a/hal/msm8974/platform.c b/hal/msm8974/platform.c
index 76cd19a..5788727 100755
--- a/hal/msm8974/platform.c
+++ b/hal/msm8974/platform.c
@@ -7570,7 +7570,8 @@
         }
     } else if (source == AUDIO_SOURCE_FM_TUNER) {
         snd_device = SND_DEVICE_IN_CAPTURE_FM;
-    } else if (source == AUDIO_SOURCE_ECHO_REFERENCE) {
+    } else if ((source == AUDIO_SOURCE_ECHO_REFERENCE) &&
+        (uc_id == USECASE_AUDIO_RECORD_ECHO_REF_EXT)) {
         snd_device = SND_DEVICE_IN_ECHO_REFERENCE;
     } else if (source == AUDIO_SOURCE_DEFAULT) {
         goto exit;
@@ -7645,7 +7646,8 @@
             snd_device = SND_DEVICE_IN_USB_HEADSET_MIC;
         } else if (compare_device_type(&in_devices, AUDIO_DEVICE_IN_FM_TUNER)) {
             snd_device = SND_DEVICE_IN_CAPTURE_FM;
-        } else if (compare_device_type(&in_devices, AUDIO_DEVICE_IN_ECHO_REFERENCE)) {
+        } else if (compare_device_type(&in_devices, AUDIO_DEVICE_IN_ECHO_REFERENCE) &&
+            (uc_id == USECASE_AUDIO_RECORD_ECHO_REF_EXT)) {
             snd_device = SND_DEVICE_IN_ECHO_REFERENCE;
         } else if (audio_extn_usb_connected(NULL) &&
                    is_usb_in_device_type(&in_devices)) {