Disable SMS delivery report for AT&T

b/26360475

Change-Id: I296baa2d99ce7b8ffcae5e48ae3ef52301f7fce0
diff --git a/assets/carrier_config_310380.xml b/assets/carrier_config_310380.xml
index a954809..578e7b0 100644
--- a/assets/carrier_config_310380.xml
+++ b/assets/carrier_config_310380.xml
@@ -5,6 +5,7 @@
 <int name="maxImageHeight" value="1944" />
 <int name="maxMessageSize" value="1048576" />
 <int name="maxImageWidth" value="2592" />
+<boolean name="enableSMSDeliveryReports" value="false" />
 <boolean name="csp_enabled_bool" value="true" />
 </carrier_config>
 </carrier_config_list>