Add acknowledgement for arity per Apache license req

Bug: 16467608
Change-Id: Id1b6875c04752a8615f71c6d6b767c0d71098618
diff --git a/NOTICE b/NOTICE
index c5b1efa..396ecc6 100644
--- a/NOTICE
+++ b/NOTICE
@@ -1,4 +1,4 @@
-
+   Calculator is
    Copyright (c) 2005-2008, The Android Open Source Project
 
    Licensed under the Apache License, Version 2.0 (the "License");
@@ -10,6 +10,16 @@
    See the License for the specific language governing permissions and
    limitations under the License.
 
+   Arity : Arithmetic Engine for Java is
+   Copyright (c) Mihai Preda
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
 
                                  Apache License
                            Version 2.0, January 2004