Removes the feature that adds strings to the user dictionary,
aka the "green highlight with a plus sign".
Bug 19237189.
Change-Id: I2387129a3add2d69d625f2ff16ed8cab3f10a735
implementation DictionaryFacilitatorImpl.java and add a java-overridable
factory DictionaryFacilitatorProvider.java used to create a
DictionaryFacilitator.
Change-Id: Id4a58ae31feaa4d12a048a772c8d76ff82fdee45