Make build for the Katib UI inside Dockerfile

[andreyvelich]

Right now, we have build for the UI inside Katib repository here: https://github.com/kubeflow/katib/tree/master/pkg/ui/v1alpha2/frontend/build.
In that case, if we make any changes in the UI we need to make a new build for that changes in the new PRs.
I think, it is not necessary. We can try to create build inside docker container, when we are building image for the Katib UI.

/assign
/cc @johnugeorge @richardsliu
/kind feature