Add getters and copy constructor to Key class

...nputmethod/accessibility/AccessibilityEntityProvider.java

...d/inputmethod/accessibility/KeyCodeDescriptionMapper.java

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

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

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

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

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

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

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

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

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

...ndroid/inputmethod/keyboard/internal/KeyboardBuilder.java

...android/inputmethod/keyboard/internal/KeyboardParams.java

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

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

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