fix: use new getUploadFileMaxSize function added to constants

This change allows the ModalDropzone to fetch the maximum allowed size via a call to getUploadFileMaxSize() defined in constants.
Additionally fixes the conversion factor (maxSize/(1024*1024) vs (1000*1000) for consistency with upstream code

Author: MuPp3t33r

src/generic/modal-dropzone/ModalDropzone.jsx

@@ -13,9 +13,9 @@ import {
 } from '@openedx/paragon';
 import { FileUpload as FileUploadIcon } from '@openedx/paragon/icons';
 
+import { getUploadFileMaxSize } from '@src/constants';
 import useModalDropzone from './useModalDropzone';
 import messages from './messages';
-import { UPLOAD_FILE_MAX_SIZE } from '../../constants';
 
 const ModalDropzone = ({
   fileTypes,
@@ -30,7 +30,7 @@ const ModalDropzone = ({
   onChange,
   onSavingStatus,
   onSelectFile,
-  maxSize = UPLOAD_FILE_MAX_SIZE,
+  maxSize,
 }) => {
   const {
     intl,
@@ -48,7 +48,7 @@ const ModalDropzone = ({
 
   const invalidSizeMore = invalidFileSizeMore || intl.formatMessage(
     messages.uploadImageDropzoneInvalidSizeMore,
-    { maxSize: maxSize / (1000 * 1000) },
+    { maxSize: (maxSize || getUploadFileMaxSize()) / (1024 * 1024) },
   );
 
   const inputComponent = previewUrl ? (
@@ -129,7 +129,7 @@ ModalDropzone.defaultProps = {
   imageHelpText: '',
   previewComponent: null,
   imageDropzoneText: '',
-  maxSize: UPLOAD_FILE_MAX_SIZE,
+  maxSize: undefind,
   invalidFileSizeMore: '',
   onSelectFile: null,
 };