Is it possible to specify multiple keys for Google Maps Android API in the same code base?
It looks like I have to change the key in manifest file each time I change keystore. It's not very convenient, imho, if you need to test the app signed with keys form debug and release keystores.
I don't think this is what you want to do. You should add both debug and release SHA1 key to API key on Google Developer API Console. Take a look at this answer