Marking vulnerable strings as untranslatable

[rapterjet2004]

• fixes There is no sound playback when sending voice messages (android). #5421

🏁 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://github.com/nextcloud/talk-android/actions/runs/26048155143/artifacts/7064357653
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)