Add new RIL command for sending ack to solicited async and unsolicited msg.

Bug: 22127517
Change-Id: I371aae330f96e5767850b8c7fabbb36984334a98
diff --git a/telephony/java/com/android/internal/telephony/RILConstants.java b/telephony/java/com/android/internal/telephony/RILConstants.java
index 3c4c04b..7d5645e 100644
--- a/telephony/java/com/android/internal/telephony/RILConstants.java
+++ b/telephony/java/com/android/internal/telephony/RILConstants.java
@@ -336,6 +336,8 @@
     int RIL_REQUEST_PULL_LCEDATA = 134;
     int RIL_REQUEST_GET_ACTIVITY_INFO = 135;
 
+    int RIL_RESPONSE_ACKNOWLEDGEMENT = 800;
+
     int RIL_UNSOL_RESPONSE_BASE = 1000;
     int RIL_UNSOL_RESPONSE_RADIO_STATE_CHANGED = 1000;
     int RIL_UNSOL_RESPONSE_CALL_STATE_CHANGED = 1001;