V2 Wizard: Disable back on first step (HMS-2781)

Disables the back button on the first step of the wizard. Disabling the
back button (as opposed to hiding it) is how the wizard works in the
Patternfly official examples.

src/Components/CreateImageWizardV2/CreateImageWizard.tsx

@@ -58,10 +58,12 @@ import { resolveRelPath } from '../../Utilities/path';
 import { ImageBuilderHeader } from '../sharedComponents/ImageBuilderHeader';
 
 type CustomWizardFooterPropType = {
+  disableBack?: boolean;
   disableNext: boolean;
 };
 
 export const CustomWizardFooter = ({
+  disableBack: disableBack,
   disableNext: disableNext,
 }: CustomWizardFooterPropType) => {
   const { goToNextStep, goToPrevStep, close } = useWizardContext();
@@ -79,6 +81,7 @@ export const CustomWizardFooter = ({
         ouiaId="wizard-back-btn"
         variant="secondary"
         onClick={goToPrevStep}
+        isDisabled={disableBack}
       >
         Back
       </Button>
@@ -160,6 +163,7 @@ const CreateImageWizard = ({ startStepIndex = 1 }: CreateImageWizardProps) => {
             footer={
               <CustomWizardFooter
                 disableNext={targetEnvironments.length === 0}
+                disableBack={true}
               />
             }
           >