=sam #16402 #16402 add explicit dependencies to samples

Only first level transitive dependencies are left, when transforming sample build definitions from library to project dependencies. Therefore explicitly add akka dependencies that samples use.

Tested on my machine and `akka-samples/multi-jvm:test` passed with success.
what does this mean? do we have to add all dependencies one-by-one?
this should normally be enough with `akka-contrib` and `akka-multi-node-testkit`