Migrate Bazel Android Tools from bazel repo to rules_android repo

[ahumesky]

The tools that the Starlark Android rules use reside in the https://github.com/bazelbuild/bazel repo, and should be moved to https://github.com/bazelbuild/rules_android

[ahumesky]

Some of the tools have been moved (aar import tools, and a few misc tools) over. The resource processor depends on Bazel's internal options parser and well as the java worker library. The processor is being moved to JCommander to break the dependency on Bazel's internal code, and the worker library is being moved to its own repository on github.