fix(view): fix DirectivePropertyGroupMemento to return a new group instead of null

Author: vsavkin

modules/core/src/compiler/view.js

@@ -535,7 +535,7 @@ class DirectivePropertyGroupMemento {
  var id = elementInjectorIndex * 100 + directiveIndex;
 
  if (! MapWrapper.contains(_groups, id)) {
- return MapWrapper.set(_groups, id, new DirectivePropertyGroupMemento(elementInjectorIndex, directiveIndex));
+ MapWrapper.set(_groups, id, new DirectivePropertyGroupMemento(elementInjectorIndex, directiveIndex));
  }
  return MapWrapper.get(_groups, id);
  }