At some places in drop-down it shows empty title (generated through form widget) and at some places it shows "Any" (in ftl).So need to make them consistent.
We can either enhance form widget render to show "Any" while rendering drop-down where allow-empty is set to true or we can change drop-down option from "Any" to empty in freemarker files.
My preference is to use empty instead of "Any". "Any" make sense on find screen but on create/update form it does not make sense. So its good idea if we use empty as generic solution.