Disable apply voucher button during submit.
Disable apply voucher button during submit.

Stop concurrent requests by disabling submit button during
submission.

PROD-301

edx/ecommerce,eduNEXT/edunext-ecommerce,edx/ecommerce,edx/ecommerce,eduNEXT/edunext-ecommerce,eduNEXT/edunext-ecommerce,eduNEXT/edunext-ecommerce,edx/ecommerce