DONTBUILD NPOTB
The :omnijar project is for IntelliJ only; adding it neatly labels
folders we consider part of the omnijar in mobile/android. The JAR
produced is not used.
We add an evaluation-time dependency from :app to :omnijar so that we
can declare the set of omnijar folders exactly once. We'd prefer to
have the dependency in the other direction (to save evaluation time)
but there's an interface mismatch between the two Gradle model types.
See comments in the :omnijar project.
This is delicate.
The sub-project definitions are still in the object directory (and
still installed by |mach gradle-install); over time, we'll migrate
them out.
The Gradle wrapper and {settings,build}.gradle in topsrcdir are
identical to those in mobile/android/gradle. I don't like the
duplication, but I also don't want the burden of keeping the two
configurations identical. We'll move away from the configuration
using mobile/android/gradle as quickly as we can.
