Add changelog for 331
This MR was automatically created from CI, https://gitlab.com/gitlab-org/gitter/gitter-android-app/-/jobs/222114075
We copied CURRENT_VERSION.txt
-> 331.txt
This MR was automatically created from CI, https://gitlab.com/gitlab-org/gitter/gitter-android-app/-/jobs/222114075
We copied CURRENT_VERSION.txt
-> 331.txt