address feedback - add more description for wipe method.
address feedback - add more description for wipe method.

AzureAD/azure-activedirectory-library-for-objc,AzureAD/azure-activedirectory-library-for-objc,AzureAD/azure-activedirectory-library-for-objc,AzureAD/azure-activedirectory-library-for-objc,AzureAD/azure-activedirectory-library-for-objc