[stable-3.8] Fix NPE in PreviewMediaFragment

[backportbot-nextcloud]

backport of #4577

[nextcloud-android-bot]

Lint

Type	stable-3.8	PR
Warnings	58	58
Errors	0	0

SpotBugs (new)

Warning Type	Number
Bad practice Warnings	24
Correctness Warnings	69
Internationalization Warnings	12
Malicious code vulnerability Warnings	4
Multithreaded correctness Warnings	9
Performance Warnings	110
Security Warnings	46
Dodgy code Warnings	137
Total	411

SpotBugs (stable-3.8)

Warning Type	Number
Bad practice Warnings	24
Correctness Warnings	69
Internationalization Warnings	12
Malicious code vulnerability Warnings	4
Multithreaded correctness Warnings	9
Performance Warnings	110
Security Warnings	46
Dodgy code Warnings	137
Total	411

[codecov]

Codecov Report

Merging #4594 into stable-3.8 will increase coverage by 0.02%.
The diff coverage is 0%.

@@               Coverage Diff                @@
##             stable-3.8    #4594      +/-   ##
================================================
+ Coverage         16.99%   17.01%   +0.02%     
  Complexity            1        1              
================================================
  Files               361      361              
  Lines             32000    32001       +1     
  Branches           4511     4512       +1     
================================================
+ Hits               5438     5445       +7     
+ Misses            25659    25652       -7     
- Partials            903      904       +1

Impacted Files	Coverage Δ	Complexity Δ
...cloud/android/ui/preview/PreviewMediaFragment.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...cloud/android/ui/activity/FileDisplayActivity.java	19.64% <0%> (-0.08%)	0% <0%> (ø)
.../third_parties/daveKoeller/AlphanumComparator.java	82.14% <0%> (ø)	0% <0%> (ø)	⬇️
...owncloud/android/ui/adapter/OCFileListAdapter.java	29.63% <0%> (+0.19%)	0% <0%> (ø)	⬇️
...loud/android/datamodel/ThumbnailsCacheManager.java	35.58% <0%> (+0.54%)	0% <0%> (ø)	⬇️
...in/java/com/owncloud/android/utils/ThemeUtils.java	51.57% <0%> (+1.57%)	0% <0%> (ø)	⬇️

[nextcloud-android-bot]

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/11070.apk



To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud app.

[nextcloud-android-bot]

Lint

Type	stable-3.8	PR
Warnings	58	58
Errors	0	0

SpotBugs (new)

Warning Type	Number
Bad practice Warnings	24
Correctness Warnings	69
Internationalization Warnings	12
Malicious code vulnerability Warnings	4
Multithreaded correctness Warnings	9
Performance Warnings	110
Security Warnings	46
Dodgy code Warnings	137
Total	411

SpotBugs (stable-3.8)

Warning Type	Number
Bad practice Warnings	24
Correctness Warnings	69
Internationalization Warnings	12
Malicious code vulnerability Warnings	4
Multithreaded correctness Warnings	9
Performance Warnings	110
Security Warnings	46
Dodgy code Warnings	137
Total	411