Az.StorageSync update for 2019-02-01 API version

[anpint]

Description

This PR contains changes required to support the new API version of Microsoft.StorageSync, 2019-02-01.
Swagger changes: Azure/azure-rest-api-specs#5210
SDK changes: Azure/azure-sdk-for-net#5596
The changes are as follows:

• rename "StorageAccountShareName" property to "AzureFileShareName" in New-AzStorageSyncCloudEndpoint
• Changes to SyncStatus property of Server Endpoint object to support parallel upload/download activity.

Checklist

• I have read the Submitting Changes section of CONTRIBUTING.md
• The title of the PR is clear and informative
• The appropriate change log has been updated
• The PR does not introduce breaking changes
• If applicable, the changes made in the PR have proper test coverage
• For public API changes to cmdlets:
  • the changes have gone through a cmdlet design review (Microsoft internal partners only)
  • the cmdlet markdown files were generated using the platyPS module

[adxsdkps]

Can one of the admins verify this patch?

[maddieclayton]

@azuresdkci Add to whitelist

[anpint]

Regarding these breaking changes:
3010 The property 'CurrentProgress' of type 'Microsoft.Azure.Commands.StorageSync.Models.PSServerEndpointHealth' has been removed.
3030 The generic type for 'property LastSyncPerItemErrorCount' has been changed from 'System.Nullable1[System.Int32]' to 'System.Nullable1[System.Int64]'.

Both of these changes reflect changes in our 2019-02-01 API version. CurrentProgress is no longer available in the protocol, nor does it make sense to keep it considering the new protocol behavior. LastSyncPerItemErrorCount was incorrectly defined as int32 in our protocol, and this has been corrected in the 2019-02-01 API version