update arrayList to CopyOnWriteArrayList

app/src/main/java/foundation/e/drive/services/InitializerService.java

@@ -32,6 +32,7 @@ import java.io.File;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
 
 import foundation.e.drive.models.SyncedFolder;
 import foundation.e.drive.operations.CreateInitialFolderRemoteOperation;
@@ -62,7 +63,7 @@ public class InitializerService extends Service
     private int restartFolderCreationCounter =0;
     private ConnectivityReceiver connectivityReceiver;
 
-    public static List<File> remoteDownloadFile=new ArrayList<>();
+    public static List<File> remoteDownloadFile=new CopyOnWriteArrayList<>();
     public static boolean schedulerFlag=false;
     public static boolean fileObserverFlag=false;