If you need to do some bulk configuration for a lot of Microsoft Team groups, you can use the available PowerShell module from here https://www.powershellgallery.com/packages/MicrosoftTeams/0.9.0
If you have this module installed, you can use the Powershell GUI from Anthony Caragol.
Anthony Caragol has create one easy to use PowerShell GUI to set the permission for several Microsoft Team groups at the same time. You can download the tool from his Blog Teamsadmin.com
Run these PowerShell script and connect to your tenant with your admin account. You will see all your MS Team group and you can modify all at once.
Many Thanks to Anthony Caragol for this helpful tool.