[FEATURE REQUEST] More improvements in gesture navigation

Follow up from: https://github.com/owncloud/android/issues/4950

Gesture navegability to improve (Android16+):

1. Browsing back from the root folder of any custom space, closes the app. Expected: moving to list of spaces:

https://github.com/user-attachments/assets/d44abadf-5ea3-4349-87e5-f9d34cbd40ea

2. Browsing back from the Details view, closes the app. Expected: moving to list of files:

https://github.com/user-attachments/assets/f17a9636-5b08-4d0c-9e56-4fa55b381afb

3. Browsing back from the text or audio preview, does nothing the first time and the second time, closes the app. Expected: moving to list of files:

https://github.com/user-attachments/assets/1ef4b9cf-e485-4fe9-b1df-e73aa395b22b

Tested with Android 16 and Android 17. With Android 15 works fine.

TASKS

• Research (if needed)
• Create branch feature/feature_name
• Development tasks
  • Implement whatever
  • ...
  • Implement unit tests (if needed)
• Code review and apply changes requested
• Design test plan
• QA
• Merge branch feature/feature_name into master

Start by reproducing the three back-navigation cases on Android 16 or 17, using the custom-space root, Details view, and text or audio preview described here and in issue 4950. Trace the app's navigation entry points for those screens and verify that back reaches the list of spaces or files instead of closing or ignoring the first gesture. Add regression coverage if the affected navigation paths have existing tests.