TF-2311 Only delete the folder when it exists

Signed-off-by: dab246 <tdvu@linagora.com>
(cherry picked from commit d3cf489cbc71bfa0c05d0c633136d504d3d9dfdd)

core/lib/utils/file_utils.dart

@@ -98,13 +98,15 @@ class FileUtils {
     return File(internalStorageDirPath).exists();
   }
 
-  void removeFolder(String folderName) async {
+  Future<void> removeFolder(String folderName) async {
     try {
       String folderPath = (await getApplicationDocumentsDirectory()).absolute.path;
       folderPath = '$folderPath/$folderName';
       log('FileUtils::removeFolder():folderPath: $folderPath');
       final dir = Directory(folderPath);
-      dir.deleteSync(recursive: true);
+      if (await dir.exists()) {
+       await dir.delete(recursive: true);
+      }
     } catch (e) {
       logError('FileUtils::removeFolder():EXCEPTION: $e');
     }

lib/features/caching/caching_manager.dart

@@ -128,10 +128,12 @@ class CachingManager {
     return await HiveCacheConfig().closeHive();
   }
 
-  void clearAllFileInStorage() {
+  Future<void> clearAllFileInStorage() async {
     if (PlatformInfo.isMobile) {
-      _fileUtils.removeFolder(CachingConstants.newEmailsContentFolderName);
-      _fileUtils.removeFolder(CachingConstants.openedEmailContentFolderName);
+      await Future.wait([
+        _fileUtils.removeFolder(CachingConstants.newEmailsContentFolderName),
+        _fileUtils.removeFolder(CachingConstants.openedEmailContentFolderName),
+      ]);
     }
   }