Go can now directly embed files without relying on external tools.
This makes code use go:embed and avoid the external tooling.
go:embed requires files to be present in the embedded directory,
hence we need to add .keep to "dist" folder. We also add one to
public/.keep, such that it won't be deleted when building multinode.
Change-Id: I53ac3d5ac76e44f740d95221acf0da99fc256d42
28c9403702