Fixing contrast for the filter conversation dialog

[rapterjet2004]

• fixes Filter Conversation options are hard to read. #4075

Just copy-pasted the code from commons and tweaked the text color to be onSecondaryContainer

🖼️ Screenshots

🏚️ Before	🏡 After

🏁 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?)

[rapterjet2004]

/backport to stable-20.0

[github-actions]

Codacy

Lint

Type	master	PR
Warnings	86	86
Errors	132	131

SpotBugs

Category	Base	New
Bad practice	6	6
Correctness	11	11
Dodgy code	78	78
Internationalization	3	3
Malicious code vulnerability	3	3
Performance	6	6
Security	1	1
Total	108	108

[github-actions]

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/4087-talk.apk



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