[BUG] Progress bar not showing up in Onboarding UI for single paged onboarding

[SMartorelli]

Describe the bug
Progress bar payload is ignored in the Onboarding UI if the onboarding payload has only one page.

To Reproduce
Onboarding Payload JSON sample:

{
   "progressBarPayload":"/percent 0 /exit_on_completion true /top_message Top Message /bottom_message Bottom Message",
   "pages":[
      {
         "title":"First page's title",
         "subtitle":"First page's subtitle",
         "body":"First page's body"
      }
   ]
}

Expected behavior
Progress bar should appear.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: macOS 14.5
• Project version > 3.0.0

Additional context
Reported by slack user Marcus Hesse in the mac-ibm-open-source channel