Computes the initial states from the default configuration: BaseState, then ON, then OFF.
public PdfOptionalContentState GetDefaultStates()
ISO 32000-2 §8.11.4.5 steps a and b. Usage and auto-state entries are not applied (that is for interactive processors and
an explicit step: ApplyAutoStates(PdfOptionalContentState, PdfOptionalContentEvent, PdfOptionalContentUsageContext)). A BaseState other than ON in D is reported and honoured
(OFF) or read as ON (Unchanged); a group in both ON and OFF is reported and ends OFF; an Intent other
than View in D is reported and honoured.