Fix InputEventKey::echo type from INT to BOOL

(cherry picked from commit 5e3c64828aacc8e166a74e3a8df0cecd408a25ef)

core/os/input_event.cpp

@@ -348,7 +348,7 @@ void InputEventKey::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "pressed"), "set_pressed", "is_pressed");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "scancode"), "set_scancode", "get_scancode");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "unicode"), "set_unicode", "get_unicode");
-	ADD_PROPERTY(PropertyInfo(Variant::INT, "echo"), "set_echo", "is_echo");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "echo"), "set_echo", "is_echo");
 }
 
 InputEventKey::InputEventKey() {