docs(numberFilter): update to match handling of null and undefined
docs(numberFilter): update to match handling of null and undefined

This changed in 26905d5e214796530a474d563b81c80df8aa79d3, where null and
undefined are passed through.

Closes #11963

ggershoni/angular.js,ggershoni/angular.js,ggershoni/angular.js,ggershoni/angular.js