Add changelog for 221
This MR was automatically created from CI, https://gitlab.com/gitlab-org/gitter/gitter-android-app/-/jobs/135843026
We copied CURRENT_VERSION.txt
-> 221.txt
This MR was automatically created from CI, https://gitlab.com/gitlab-org/gitter/gitter-android-app/-/jobs/135843026
We copied CURRENT_VERSION.txt
-> 221.txt