Define Verizon IMS conference size limit.

Change-Id: I38ec689c598e86b51ac738e951bb974a955c45d4
Test: Manual
Bug: 29548224
diff --git a/assets/carrier_config_311480.xml b/assets/carrier_config_311480.xml
index 3ed714e..a0874ca 100644
--- a/assets/carrier_config_311480.xml
+++ b/assets/carrier_config_311480.xml
@@ -106,6 +106,8 @@
             <item value="dun" />
             <item value="supl" />
         </string-array>
+        <boolean name="is_ims_conference_size_enforced_bool" value="true"/>
+        <int name="ims_conference_size_limit_int" value="5" />
     </carrier_config>
     <!-- Tracfone Vzw shows empty string as SPN -->
     <carrier_config gid1="BA01270000000000">