There are two project layouts possible. One is that each sub-project
is its own Gradle project with its own copy of the Gradle wrapper,
project configurations, etc. The other is that there's one
multi-project with sub-Gradle projects.
Generally the multi-project approach, even for decoupled projects, is
simpler. The `android-components` repository uses it, even though its
projects are very explicitly decoupled in most cases.
Nick Alexander