LatinIME: Completely remove language switch key

The language picker globe button is now handled by the SystemUI navigation hint IME. Because of this, we get a redundant globe on the stock keyboard. Removing the globe in the keyboard makes the most sense, as it can not be turned off otherwise

Author: 306bobby-android

common/src/com/android/inputmethod/latin/common/Constants.java

@@ -240,7 +240,6 @@ public static boolean isValidCoordinate(final int coordinate) {
     public static final int CODE_SHORTCUT = -7;
     public static final int CODE_ACTION_NEXT = -8;
     public static final int CODE_ACTION_PREVIOUS = -9;
-    public static final int CODE_LANGUAGE_SWITCH = -10;
     public static final int CODE_EMOJI = -11;
     public static final int CODE_SHIFT_ENTER = -12;
     public static final int CODE_SYMBOL_SHIFT = -13;
@@ -265,7 +264,6 @@ public static String printableCode(final int code) {
         case CODE_SHORTCUT: return "shortcut";
         case CODE_ACTION_NEXT: return "actionNext";
         case CODE_ACTION_PREVIOUS: return "actionPrevious";
-        case CODE_LANGUAGE_SWITCH: return "languageSwitch";
         case CODE_EMOJI: return "emoji";
         case CODE_SHIFT_ENTER: return "shiftEnter";
         case CODE_ALPHA_FROM_EMOJI: return "alpha";