--online-discard option defined as string parameter since it doesn't
specify "action=", but has default value in boolean (default=True).
It breaks "provisioning in a similar environment" since the code
supposed boolean value should be "action='store_true'" but it's not.
We should change the type of the option to int, and also specify
"choices=[0, 1]" just like --io-setup does.
Fixes#11700Closes#11831