Switch WaitNamedPipe and CreateNamedPipeClient invocation ordering. (dotnet/corefx#24616)
* Switch WaitNamedPipe and CreateNamedPipeClient invocation ordering.
We need to do this as WaitNamedPipe is not supported in Windows Containers.
By default using CreateNamedPipeClient first with call to WaitNamedPipe as
a fallback only will allow us to use NamedPipeClientStream inside Windows
Containers.
* Integrate feedback from PR.
Commit migrated from https://github.com/dotnet/corefx/commit/
e003701727df908d6eb7ba7b814c74924c498377