I'm in the process of trying to set this up myself (sadly English weather has rolled in). I haven't gotten it to appear in the web manager yet but I did get it working by doing an "apt-get update" and "apt-get upgrade" *after* doing the apt-get install indi-rpicam. It then at least was functional in Ekos after that.
Also as mentioned on another forum post there's a command to spin up the indiserver from the console screen: indiserver -v indi_rpicam . I'm mentioning here in case you go that route and also get tripped up that the package name has a - and the actual driver has a _. That forum post can be found here:
Don't know if that helps or not