Add ASSIST keycode.

    AKEYCODE_YEN             = 216,

    AKEYCODE_RO              = 217,

    AKEYCODE_KANA            = 218,

    AKEYCODE_ASSIST          = 219,

    // NOTE: If you add a new keycode here you must also add it to several other files.

    //       Refer to frameworks/base/core/java/android/view/KeyEvent.java for the full list.