Update LICENSE (#2601)

Changes to comply with internal review

Author: franklinyow

LICENSE

@@ -1,4 +1,5 @@
-Copyright 2014, the Dart project authors. All rights reserved.
+Copyright 2014, the Dart project authors. 
+
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are
 met:
@@ -9,7 +10,7 @@ met:
       copyright notice, this list of conditions and the following
       disclaimer in the documentation and/or other materials provided
       with the distribution.
-    * Neither the name of Google Inc. nor the names of its
+    * Neither the name of Google LLC nor the names of its
       contributors may be used to endorse or promote products derived
       from this software without specific prior written permission.