volume_listener: Update prefixes for audio system properties

-Vendor created android properties are required to have
 vendor prefixes. Update vendor specific audio system
 property configs

Change-Id: I8a0e8a858eba6e63f134cbb0816704b2b75f521f
diff --git a/post_proc/volume_listener.c b/post_proc/volume_listener.c
index 635fe23..a8c2c53 100644
--- a/post_proc/volume_listener.c
+++ b/post_proc/volume_listener.c
@@ -677,7 +677,7 @@
 
     // check system property to see if dumping is required
     char check_dump_val[PROPERTY_VALUE_MAX];
-    property_get("audio.volume.listener.dump", check_dump_val, "0");
+    property_get("vendor.audio.volume.listener.dump", check_dump_val, "0");
     if (atoi(check_dump_val)) {
         dumping_enabled = true;
     }