[Bug]: File list does not refresh automatically after granting storage permission

[yxXXxy999]

Describe the bug
After granting storage permission for the first time, the file manager does not automatically refresh the file list after file creation or deletion operations.

After the user navigates to another folder, everything returns to normal.

To Reproduce
Steps to reproduce the behavior:

1. Open the app and grant storage permissions when prompted.
2. Perform a file creation or deletion operation.
3. The file list does not update.

Screen recording
https://github.com/user-attachments/assets/ae3fc1af-da21-4a4c-8abe-0b2d71707ab0

Expected behavior
The file list should automatically refresh and reflect any creation or deletion operations all the time.

Device Information:

• Device: generic_x86_64 (Android Studio x86 emulator)
• OS: Android 9

[zhanghai]

This is probably due to the file observer not being re-registered after the permission is granted.