Revert "Support Emoji keyboard"

java/res/layout/input_view.xml

java/res/values/emoji-categories.xml

java/res/values/themes-common.xml

java/res/values/themes-gb.xml

java/res/values/themes-ics.xml

java/res/xml-sw600dp/key_f2.xml

java/res/xml-sw600dp/key_styles_common.xml

java/res/xml-sw768dp/key_styles_common.xml

java/res/xml/key_styles_common.xml

java/res/xml/row_symbols4.xml

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

.../android/inputmethod/keyboard/internal/KeyboardState.java

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

...d/inputmethod/keyboard/internal/MockKeyboardSwitcher.java