Today i also (!!!) activated 'Allow installation' and set it to 'Always allow installs (recommended)' on both pathes shown above (again, propably over defined). My settings up to now where to activate 'Update Policy override default' and set it to 'Always allow updates (recommended)' on both Computer Configuration->Adminstrative templates->Google->Google Update->Applications and Computer Configuration->Adminstrative templates->Google->Google Update->Applications->Google Chrome (which is propably a bit over defined, either of them should be enough). I've also struggled with this issue for some time now, but today i was successful.