2048: Do not default to only temporarily applying settings changes

Also tweak its text in the settings window to be clearer on what this
check box is doing. Seemed a bit confusing that settings changes
required an extra action to persist.

Userland/Games/2048/GameSizeDialog.h

@@ -23,5 +23,5 @@ private:
     size_t m_board_size;
     size_t m_target_tile_power;
     bool m_evil_ai;
-    bool m_temporary { true };
+    bool m_temporary { false };
 };