Fixed a bug where post reminder modal didn't close (#29615)

* Fixed  abug where post reminder modal didnt close

* Fixed a test

webapp/platform/components/src/generic_modal/__snapshots__/generic_modal.test.tsx.snap

@@ -11,7 +11,7 @@ exports[`GenericModal should match snapshot for base case 1`] = `
       aria-hidden="true"
     />
     <div
-      role="dialog"
+      role="none"
     >
       <div
         class="fade modal-backdrop in"