Support colorScheme <case/> condition in Keyboard XML

java/res/layout/input_stone_bold.xml

java/res/layout/input_stone_normal.xml

java/res/values/attrs.xml

java/res/values/styles.xml

java/res/xml-da/kbd_qwerty_black.xml

java/res/xml-de/kbd_qwerty_black.xml

java/res/xml-fr/kbd_qwerty_black.xml

java/res/xml-iw/kbd_qwerty_black.xml

java/res/xml-nb/kbd_qwerty_black.xml

java/res/xml-ru/kbd_qwerty_black.xml

java/res/xml-sr/kbd_qwerty_black.xml

java/res/xml-sv/kbd_qwerty_black.xml

java/res/xml-xlarge/kbd_symbols.xml

java/res/xml/kbd_functional_key_style.xml

java/res/xml/kbd_key_styles.xml

java/res/xml/kbd_phone.xml

java/res/xml/kbd_phone_black.xml

java/res/xml/kbd_phone_symbols.xml

java/res/xml/kbd_phone_symbols_black.xml

java/res/xml/kbd_qwerty.xml