Fix some cases where the read marker line would not show up when it should

[SpiritCroc]

Signed-off-by: Tobias Büttner [email protected]

Type of change

• Feature
• Bugfix
• Technical
• Other :

Tests

1. Permalink the latest message in a chat
2. Close the chat
3. Receive lots of messages
4. Open the chat at the permalink and see if the unread messages line shows up

Tested devices

• Physical
• Emulator
• OS version(s): Android 11

Checklist

• Changes has been tested on an Android device or Android emulator with API 21
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com./vector-im/element-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request includes a new file under ./changelog.d. See https://github.com./vector-im/element-android/blob/develop/CONTRIBUTING.md#changelog
• Pull request includes screenshots or videos if containing UI changes
• Pull request includes a sign off
• You've made a self review of your PR
• If you have modified the screen flow, or added new screens to the application, you have updated the test UiAllScreensSanityTest.allScreensTest()

[ganfra]

LGTM thanks