Timestamps shown with AM/PM despite 24 hour locale

**Describe the bug**
On both the room list and in individual rooms, message timestamps are shown in 12 hour AM/PM format, despite my phone being set to British English locale with 24 hour clock everywhere else.

**To Reproduce**
Steps to reproduce the behavior:
1. Go to the room list
2. Observe 12 hour timestamps
3. Select a room
4. Observe 12 hour timestamps

**Expected behavior**
Observe 24 hour timestamps

**Smartphone (please complete the following information):**
- Device: Pixel 2
- OS: Android 11

**Additional context**
- App version and store: 1.0.9 Google Play
- Homeserver: ilmari.org

I have seen this happen with 1.0.8 too, but only transiently. With 1.0.9 it seems to be permanently stuck. Clearing the cache (both in the app itself, and in the system app info) and force stopping the app did not help.