MDL-83661 core_courseformat: fix drop file modal

When the user drags and drops a file into a course section that can
create more than one type of activity (for example a zip file) the modal
had repeated form elements ids. Now every radio option has its own id.

course/format/amd/src/local/courseeditor/fileuploader.js

@@ -345,10 +345,11 @@ class HandlerManager {
         let hasDefault = false;
         fileHandlers.forEach((handler, index) => {
             const isDefault = (defaultModule == handler.module);
+            const optionNumber = index + 1;
             data.handlers.push({
                 ...handler,
                 selected: isDefault,
-                labelid: `fileuploader_${data.uploadid}`,
+                labelid: `fileuploader_${data.uploadid}_${optionNumber}`,
                 value: index,
             });
             hasDefault = hasDefault || isDefault;