The update channel setting in the Android apps (Logos, Faithlife and Vyrso) can be found in the 'About' page. There shouldn't be a need to press 'Enter' or 'Done' on your keyboard. As you type, the app checks to see if the channel exists. If it does, it displays either a checkmark or a download icon as you can see in the screen grabs below.
The check mark indicates that the channel exists and that you already have the latest version installed.
The download icon indicates there's an update available. Tapping that icon will open a browser window with a link to the application.
