use boolean data-json-type for ability use `true`/`false` value as string

gadget_json_generated_form_child.js

@@ -86,6 +86,7 @@
       schema_for_selection.default = schema.default;
     }
     input = render_selection(schema_for_selection, json_document);
+    input.setAttribute('data-json-type', "boolean");
     return input;
   }
 
@@ -1092,12 +1093,15 @@
           k;
         g.props.inputs.forEach(function (input) {
           if (input.required || input.value !== "") {
+            var type = input.getAttribute('data-json-type');
             if (input.type === 'number') {
               json_dict[input.name] = parseInt(input.value, 10);
-            } else if (input.value === "true") {
+            } else if (type === "boolean") {
+              if (input.value === "true") {
                 json_dict[input.name] = true;
               } else if (input.value === "false") {
                 json_dict[input.name] = false;
+              }
             } else if (input.tagName === "TEXTAREA") {
               if (input["data-format"] === "string") {
                 json_dict[input.name] = input.value;