Checking if file exists before creating the empty file in CreateFolderAsync

[stephen-moyer]

Fixes

AccessDenied exceptions when creating a folder in disk blob storage from two processes at the same time.

Description

When running multiple processes pointed to the same disk blob storage directory, running CreateFolderAsync at the same path on both services can cause AccessDenied exceptions because both processes are trying to create the .empty file.

The process cannot access the file 'C:\\datamover\\health_check\\.empty' because it is being used by another process.

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