[jit][edge] Create DynamicType for OptionalType in mobile. (#68137)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68137
A small step to replace existing OptionalType usage to DynamicType in Edge runtime.
ghstack-source-id: 146670520
Test Plan: CI
Reviewed By: iseeyuan
Differential Revision: D32264617
fbshipit-source-id: 62d3ffad40901842deac19ca2098ea5ca132e718
