fix(gallery-fragment): illegal state exception

[alperozturk96]

Issue

Exception java.lang.IllegalStateException:
  at androidx.fragment.app.Fragment.requireActivity (Fragment.java:1005)
  at com.owncloud.android.ui.fragment.GalleryFragment.updateSubtitle (GalleryFragment.java:410)
  at com.owncloud.android.ui.fragment.GalleryFragment.showAllGalleryItems (GalleryFragment.java:406)
  at com.owncloud.android.ui.fragment.GalleryFragment.searchCompleted (GalleryFragment.java:278)
  at com.owncloud.android.ui.asynctasks.GallerySearchTask.onPostExecute (GallerySearchTask.java:104)
  at com.owncloud.android.ui.asynctasks.GallerySearchTask.onPostExecute (GallerySearchTask.java:33)
  at android.os.AsyncTask.finish (AsyncTask.java:771)
  at android.os.AsyncTask.-$$Nest$mfinish (Unknown Source)
  at android.os.AsyncTask$InternalHandler.handleMessage (AsyncTask.java:788)
  at android.os.Handler.dispatchMessage (Handler.java:107)
  at android.os.Looper.loopOnce (Looper.java:232)
  at android.os.Looper.loop (Looper.java:317)
  at android.app.ActivityThread.main (ActivityThread.java:8751)
  at java.lang.reflect.Method.invoke
  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:580)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:892)

[github-actions]

Codacy

SpotBugs

Category	Base	New
Bad practice	36	36
Correctness	69	69
Dodgy code	229	229
Experimental	1	1
Internationalization	7	7
Malicious code vulnerability	2	2
Multithreaded correctness	34	34
Performance	42	42
Security	16	16
Total	436	436

[github-actions]

APK file: https://github.com/nextcloud/android/actions/runs/24122304240/artifacts/6322079016
To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud app.
(please click on link to get QR code displayed)

[github-actions]

blue-Light-Screenshot test failed, but no output was generated. Maybe a preliminary stage failed.