message: Fix bug: CopyBlob always sends empty access-tier header
diff: @@ -551,7 +551,7 @@ namespace Azure { namespace Storage { namespace Blobs {
  /**
  * @brief Specifies the tier to be set on the target blob.
  */
  - Azure::Core::Nullable<AccessTier> Tier = AccessTier::Unknown;
  + Azure::Core::Nullable<AccessTier> Tier;
  /**
  * @beirf Indicates the priority with which to rehydrate an archived blob. The priority
  