[mob][photos] Request for ACCESS_MEDIA_LOCATION permission if not granted (#1600)

## Description


a5d05decf2/mobile/lib/utils/photo_manager_util.dart (L8)

^passing true here should let the app have `ACCESS_MEDIA_LOCATION`
permission. But looks like that isn't working for a small set of users.
So, asking for permission explicitly.

mobile/lib/utils/file_uploader.dart

@@ -376,7 +376,13 @@ class FileUploader {
     if (Platform.isAndroid) {
       final bool hasPermission = await Permission.accessMediaLocation.isGranted;
       if (!hasPermission) {
-        throw NoMediaLocationAccessError();
+        final permissionStatus = await Permission.accessMediaLocation.request();
+        if (!permissionStatus.isGranted) {
+          _logger.severe(
+            "Media location access denied with permission status: ${permissionStatus.name}",
+          );
+          throw NoMediaLocationAccessError();
+        }
       }
     }
   }