Which customers do you try to target ? High End Smartphone Users(Xperia Z, Galaxy S3-S4, Htc One) or also the old ones ? Do you target only Phones or also tablets ?
For the older ones you should try to stay under 50 mb. But dont trust C2 with the memory use ;) If you exportet you application check it with Eclipse Memory analyzer, it is mostly much lower than c2 told you ;)