Add custom info plist and entitilements keys. (#2721)

Summary:
Pull Request resolved: https://github.com/pytorch/executorch/pull/2721

Those will allow file sharing and increase the memory limit.

Reviewed By: guangy10, kirklandsign

Differential Revision: D55441271

fbshipit-source-id: a897d18b97f71d13f478aa5248624cb7fdaceabe