Add changelog for 428
This MR was automatically created from CI, https://gitlab.com/gitlab-org/gitter/gitter-android-app/-/jobs/486526571
We copied CURRENT_VERSION.txt
-> 428.txt
This MR was automatically created from CI, https://gitlab.com/gitlab-org/gitter/gitter-android-app/-/jobs/486526571
We copied CURRENT_VERSION.txt
-> 428.txt