util,finagle: Turn off scaladoc generation for benchmarks and examples
util,finagle: Turn off scaladoc generation for benchmarks and examples

Problem/Solution

We'd like to skip scaladoc generation for projects where it is not
useful and wastes resources to generate them.

RB_ID=906847

twitter/finagle,luciferous/finagle,luciferous/finagle,koshelev/finagle,mkhq/finagle,twitter/finagle,mkhq/finagle,mkhq/finagle,spockz/finagle,koshelev/finagle,koshelev/finagle,spockz/finagle,twitter/finagle,luciferous/finagle,twitter/finagle,mkhq/finagle,spockz/finagle,luciferous/finagle,koshelev/finagle,koshelev/finagle,spockz/finagle,spockz/finagle,mkhq/finagle,spockz/finagle,mkhq/finagle,luciferous/finagle,twitter/finagle,luciferous/finagle,koshelev/finagle