hal: Disable keep alive feature by default

Disable keep alive feature by setting default property value
as true.

Change-Id: If8cd5c33fde243b9492888f5a0d662d28d93fea8
diff --git a/hal/audio_extn/keep_alive.c b/hal/audio_extn/keep_alive.c
index ce2cbda..90875d9 100644
--- a/hal/audio_extn/keep_alive.c
+++ b/hal/audio_extn/keep_alive.c
@@ -120,7 +120,7 @@
     ka.state = STATE_IDLE;
     ka.pcm = NULL;
     pthread_condattr_t attr;
-    if (property_get_bool("vendor.audio.keep_alive.disabled", false)) {
+    if (property_get_bool("vendor.audio.keep_alive.disabled", true)) {
         ALOGE("keep alive disabled");
         ka.state = STATE_DISABLED;
         return;