fix(drupal): Use public file system for PDF uploads

Changed upload location from private:// to public:// for demo simplicity.
The private file system requires additional directory setup that may fail
on fresh deployments.

Author: chrisns

cloudformation/scenarios/localgov-drupal/drupal/web/modules/custom/ndx_aws_ai/src/Form/PdfConversionForm.php

@@ -85,7 +85,7 @@ public function buildForm(array $form, FormStateInterface $form_state): array {
       '#description' => $this->t('Upload a PDF file (maximum @size MB).', [
         '@size' => self::MAX_UPLOAD_SIZE_MB,
       ]),
-      '#upload_location' => 'private://pdf_conversion/',
+      '#upload_location' => 'public://pdf_conversion/',
       '#upload_validators' => [
         'file_validate_extensions' => ['pdf'],
         'file_validate_size' => [self::MAX_UPLOAD_SIZE_MB * 1024 * 1024],