🖼️ Show images in message notifications

[AndyScherzinger]

• Resolves The ability to preview media such as images in the android notification tray. #2300
• Currently a simple check if the message ships an image info and if so, display it.

To discuss: Is this "good enough" for a first implementation? what hardening should we add? I remember thinking we only have 2 preview sizes, so using the optimal notification size might be nonesense (or I am wrong with this assumption). Also I tested it with sermo, if the server doesn't provide a preview, the notification just shows the text (tested png vs svg)

🖼️ Screenshots

🚧 TODO

• discuss hardening

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not needed
• 🔖 Capability is checked or not needed
• 🔙 Backport requests are created or not needed: /backport to stable-xx.x
• 📅 Milestone is set
• 🌸 PR title is meaningful (if it should be in the changelog: is it meaningful to users?)

[github-actions]

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/5909.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]

Codacy

Lint

Type	master	PR
Warnings	98	98
Errors	0	0

SpotBugs

Category	Base	New
Bad practice	6	6
Correctness	10	10
Dodgy code	54	54
Internationalization	3	3
Malicious code vulnerability	3	3
Performance	4	4
Security	1	1
Total	81	81