Merge "Separate functional key background from normal one"

java/res/drawable/btn_keyboard_key_ics.xml

java/res/drawable/btn_keyboard_key_klp.xml

java/res/drawable/btn_keyboard_key_lmp.xml

java/res/values/attrs.xml

java/res/values/themes-common.xml

java/res/values/themes-ics.xml

java/res/values/themes-klp.xml

java/res/values/themes-lmp.xml

...c/com/android/inputmethod/keyboard/EmojiPalettesView.java

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

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

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