Implement Call handover initiation side APIs.

Bug: 65415068
Test: Manual

Design doc:
https://docs.google.com/document/d/1qY3oAzjff_4A1ttYb_CGrE_OwTRmXMG_KGsIuPT1ey8/edit#

Change-Id: I692bb14fba66733154378c2dda525aa85c471a38
Merged-in: I692bb14fba66733154378c2dda525aa85c471a38
diff --git a/telecomm/java/android/telecom/InCallService.java b/telecomm/java/android/telecom/InCallService.java
index d558bba..74fa62d 100644
--- a/telecomm/java/android/telecom/InCallService.java
+++ b/telecomm/java/android/telecom/InCallService.java
@@ -80,6 +80,7 @@
     private static final int MSG_ON_CONNECTION_EVENT = 9;
     private static final int MSG_ON_RTT_UPGRADE_REQUEST = 10;
     private static final int MSG_ON_RTT_INITIATION_FAILURE = 11;
+    private static final int MSG_ON_HANDOVER_FAILED = 12;
 
     /** Default Handler used to consolidate binder method calls onto a single thread. */
     private final Handler mHandler = new Handler(Looper.getMainLooper()) {
@@ -150,6 +151,12 @@
                     mPhone.internalOnRttInitiationFailure(callId, reason);
                     break;
                 }
+                case MSG_ON_HANDOVER_FAILED: {
+                    String callId = (String) msg.obj;
+                    int error = msg.arg1;
+                    mPhone.internalOnHandoverFailed(callId, error);
+                    break;
+                }
                 default:
                     break;
             }
@@ -225,6 +232,11 @@
         public void onRttInitiationFailure(String callId, int reason) {
             mHandler.obtainMessage(MSG_ON_RTT_INITIATION_FAILURE, reason, 0, callId).sendToTarget();
         }
+
+        @Override
+        public void onHandoverFailed(String callId, int error) {
+            mHandler.obtainMessage(MSG_ON_HANDOVER_FAILED, error, 0, callId).sendToTarget();
+        }
     }
 
     private Phone.Listener mPhoneListener = new Phone.Listener() {