This feature is still missing in the platform.
Currently, The Division 2 has a Stadia specific bug where the bindings don't save. I rather not play until this is fixed. i've no way of knowing when the fix happens--if it ever happens.
This is a bit more than the usual 'bug fixes and performance improvements' that Google uses in their own software. As Platform owner, maybe Stadia can require more from the Studios.
Would be nice if there was some acknowledgement that the feature is planned.