Add singleton CallContext.Default (#1740)
Add singleton CallContext.Default (#1740)


AzureAD/azure-activedirectory-identitymodel-extensions-for-dotnet,AzureAD/azure-activedirectory-identitymodel-extensions-for-dotnet,AzureAD/azure-activedirectory-identitymodel-extensions-for-dotnet,AzureAD/azure-activedirectory-identitymodel-extensions-for-dotnet