[Index Management] Fix Flashing error banner in Index Template form (e…

…lastic#196786)

## Summary

Fixes elastic#194751 

In `EuiForm`, if the value of `isInvalid` is true, it will render
addressFormErrors tip messages.

And In `step_logistics.tsx`, `isInValid` is setted by
`isInvalid={isSubmitted && !isFormValid}`

But form `submit` method set `isSubmitted` to true first, then validate
form. At this time, `isSubmitted is true` and `isFormValid is
unedfined`. So addressFormErrors shows immediately.


![image](https://github.com/user-attachments/assets/687a359d-ed33-4860-8d96-4543f2ef4898)

**So, maybe when `isSubmitting` is true, addressFormErrors should not be
shown.**

Co-authored-by: Elastic Machine <[email protected]>

x-pack/plugins/index_management/public/application/components/template_form/steps/step_logistics.tsx

@@ -194,6 +194,7 @@ export const StepLogistics: React.FunctionComponent<Props> = React.memo(
     const {
       submit,
       isSubmitted,
+      isSubmitting,
       isValid: isFormValid,
       getErrors: getFormErrors,
       getFormData,
@@ -275,7 +276,7 @@ export const StepLogistics: React.FunctionComponent<Props> = React.memo(
 
         <Form
           form={form}
-          isInvalid={isSubmitted && !isFormValid}
+          isInvalid={isSubmitted && !isSubmitting && !isFormValid}
           error={getFormErrors()}
           data-test-subj="stepLogistics"
         >