Rename and consolidate some constants

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

.../android/inputmethod/keyboard/KeyboardActionListener.java

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

...om/android/inputmethod/keyboard/MoreKeysKeyboardView.java

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

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

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

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

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

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

...latin/spellcheck/AndroidWordLevelSpellCheckerSession.java

...putmethod/latin/spellcheck/SpellCheckerProximityInfo.java

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

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