[AC2] Reference a dict rather than a string in suggestion infos

java/src/com/android/inputmethod/latin/BinaryDictionary.java

java/src/com/android/inputmethod/latin/Dictionary.java

...c/com/android/inputmethod/latin/ExpandableDictionary.java

java/src/com/android/inputmethod/latin/LatinIME.java

java/src/com/android/inputmethod/latin/Suggest.java

java/src/com/android/inputmethod/latin/SuggestedWords.java

...om/android/inputmethod/latin/settings/SettingsValues.java

java/src/com/android/inputmethod/research/JsonUtils.java

tests/src/com/android/inputmethod/latin/InputTestsBase.java

...rc/com/android/inputmethod/latin/SuggestedWordsTests.java