Android bindings should manage the size of the CCR thread pool

If the client code conflict resolver takes a long time to run, the library can exhaust system concurrency resources. When this happens the application will fail with a RejectedExecutionException, often in one of the SerialExecutors, and far, far from the source of the problem. It would be better to fail in some way that made it clear that slow conflict resolvers were the source of the problem.