Move reference char/digit width/height method to TypefaceUtils

java/src/com/android/inputmethod/keyboard/KeyboardView.java

...rc/com/android/inputmethod/keyboard/MainKeyboardView.java

...rc/com/android/inputmethod/keyboard/MoreKeysKeyboard.java

...ndroid/inputmethod/latin/suggestions/MoreSuggestions.java

...rc/com/android/inputmethod/latin/utils/TypefaceUtils.java