Google Maps for Android has lost its Uber booking feature, meaning users can no longer book Uber ride requests within the Google Maps app on their device. The consolidation of this feature meant users would have an easier time booking a ride if they were already in Maps but also needed to request an Uber as they wouldn't have to go into both applications, but now it seems that users will be required to go back to using both apps. That said, users will still be able to see rides in Maps and see the cost of the ride that they may want to select.
Going forward, if users are in Google Maps and do find a ride, they'll be taken outside of Maps to the actual Uber app to book the request, which is how things work with Lyft and other ride-sharing services that can be seen in the Maps platform. If you'e never used this feature inside Maps before, when you open up the directions feature you can tap on the ride-hailing icon and this will list the different options for you that are available in your area, then simply tap the booking option and you'll be re-directed to the corresponding app to finish off the request.
It doesn't appear that Google is intending to ever bring the ability to book from Maps back at any point in time, but if you've never used it before then you aren't really missing anything anyways. There's no explanation from Google as to why the feature was removed, but Google does at least explain to users that booking within Maps is no longer an option for those that may have not been aware of the change. Although you can still see the cost of Uber and Lyft rides within Maps, you can also see those costs in their respective applications, so you'll be saving yourself some time if you go straight to those apps in the first place.