Update : Official Change-logs:
• Audio Calls now available
• Bug fixes and product improvements
Official change-log saying that the app got the performance improvement and the bug fixes.
We are finding the exact change-log, means which bugs, they have fixed and which particular feature got improved in this update.
Will keep this post update with the changes and the new feature, once we done with the full research.
One new thing I noticed about Duo is Google added it in the Google play native apps groups. So the customized Android OS device users can't uninstall the app and they will get the Duo app already installed in the phone. Yesterday I updated my Mi 5 India version. Just after completing the updating process i realize that Duo automatically got installed in my phone and there is no option I found to uninstall it.
Click Below link to download the APK File of this update
Google Duo v9.1.15