Add bind() function to the binder interface.

Update engine may have started and done some work before we call
applyPayload(). Add a new binder function bind() to register a
callback function that communicates with the update engine.

Bug: None
Test: 'mmma system/update_engine'.
Change-Id: Iafcdb250904b44f9526be15f0381690df50805a2
diff --git a/Android.mk b/Android.mk
index fa6c067..aa20b29 100644
--- a/Android.mk
+++ b/Android.mk
@@ -369,7 +369,7 @@
     libutils
 LOCAL_SRC_FILES := \
     binder_bindings/android/os/IUpdateEngine.aidl \
-    binder_bindings/android/os/IUpdateEnginePayloadApplicationCallback.aidl \
+    binder_bindings/android/os/IUpdateEngineCallback.aidl \
     binder_main.cc \
     binder_service.cc