Update azuresdkdrop workflow with auth mode

[Timothyw0]

Issue:

WARNING: There are no credentials provided in your command and environment, we will query for account key for your storage account. It is recommended to provide --connection-string, --account-key or --sas-token in your command as credentials. You also can add `--auth-mode login` in your command to use Azure Active Directory (Azure AD) for authorization if your login account is assigned required RBAC roles. For more information about RBAC roles in storage, visit https://docs.microsoft.com/azure/storage/common/storage-auth-aad-rbac-cli. 

Fix:
Add --auth-mode login in az storage blob upload command to use AAD authorization which has been trusted by Azure SDK