Deprecate OwncloudClient - Notifications

[ZetaTom]

This is one of a series of pull requests which aim to replace all instances of OwnCloudClient with NextcloudClient. The reason for this change is that the newer NextcloudClient uses OkHttp, replacing the outdated Jackrabbit methods.

Specifically, this pull request implements the following:

• changes related to notifications
• see Deprecate OwncloudClient - Notifications android-library#1272

---

• Tests written, or not not needed

[github-actions]

Hello there,
Thank you so much for taking the time and effort to create a pull request to our Nextcloud project.

We hope that the review process is going smooth and is helpful for you. We want to ensure your pull request is reviewed to your satisfaction. If you have a moment, our community management team would very much appreciate your feedback on your experience with this PR review process.

Your feedback is valuable to us as we continuously strive to improve our community developer experience. Please take a moment to complete our short survey by clicking on the following link: https://cloud.nextcloud.com/apps/forms/s/i9Ago4EQRZ7TWxjfmeEpPkf6

Thank you for contributing to Nextcloud and we hope to hear from you soon!

[github-actions]

Codacy

Lint

Type	master	PR
Warnings	69	69
Errors	3	3

SpotBugs

Category	Base	New
Bad practice	64	64
Correctness	69	68
Dodgy code	344	344
Experimental	1	1
Internationalization	7	7
Multithreaded correctness	6	6
Performance	57	57
Security	19	18
Total	567	565

[github-actions]

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/12266.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.

[github-actions]

blue-Light-Screenshot test failed: https://www.kaminsky.me/nc-dev/android-integrationTests/12266-Screenshot-blue-Light-06-38