[PyTorch] Rename XPLAT_MOBILE_BUILD to TEMPLATE_SELECTIVE_BUILD (#54217)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/54217
As title. Find all XPLAT_MOBILE_BUILD usage: [search result](https://www.internalfb.com/intern/codesearch/?bunny_arg=XPLAT_MOBILE_BUILD&bunny_command=fbgs&lucky=0&q=repo%3Afbcode%20case%3Ainsensitive%20regex%3Aoff%20XPLAT_MOBILE_BUILD&source=redirect) and replace.
Since template selective build is added in OSS, rename the macro to make it clearer.
T86478520 to follow up to unify XPLAT_MOBILE_BUILD (rename to TEMPLATE_SELECTIVE_BUILD), C10_MOBILE and BUILD_LITE_INTERPRETER macros.
ghstack-source-id: 124206354
Test Plan: CI
Reviewed By: dhruvbird, iseeyuan
Differential Revision: D27112046
fbshipit-source-id: 6f89b168c1f39c5449c8ed6538d887ea066a2225
