The InstantiatingGrpcChannelProvider.withExecutor method requires ScheduledExecutorService, and similarly the InstantiatingGrpcChannelProvider$Builder. setExecutorProvider requires a ExecutorProvider(which provides ScheduledExecutorService), but this requirement seems overly strict, because the executor is only used for ManagedChannelBuilder.executor, which takes Executor rather than ScheduledExecutorService.

This unnecessary restriction prevents users from providing a more performant executor (e.g. ForkJoinPool) than ScheduledThreadPoolExecutor when building a gRPC channel.