Android: Extend the API with the payload offset and size.

The payload offset and size of the CrAU binary file inside the .zip
file are required parameters to properly apply the payload so we
explicitly required them in the API.

The update_engine_client command was extended to support these two
parameters.

Bug: 25631767
TEST=`mmma system/update_engine` on aosp_arm-eng.

Change-Id: Id5ef2f45b711039309173cb0309b9fe5cc82e485
diff --git a/binder_service_android.cc b/binder_service_android.cc
index 144836a..98943a2 100644
--- a/binder_service_android.cc
+++ b/binder_service_android.cc
@@ -47,6 +47,8 @@
 
 Status BinderUpdateEngineAndroidService::applyPayload(
     const String16& url,
+    int64_t payload_offset,
+    int64_t payload_size,
     const vector<String16>& header_kv_pairs) {
   return Status::ok();
 }