[PAYM-633] Added check to prevent code from running if bannerId is undefined
[PAYM-633] Added check to prevent code from running if bannerId is undefined

tmikus/assets-frontend,xnejp03/assets-frontend,alexanderjamesking/assets-frontend,alexanderjamesking/assets-frontend,tmikus/assets-frontend,hmrc/assets-frontend,xnejp03/assets-frontend,hmrc/assets-frontend,tmikus/assets-frontend,alexanderjamesking/assets-frontend,xnejp03/assets-frontend,hmrc/assets-frontend