Includes instructions on how to expose new public resource IDs
and how to "remove" unused resource IDs before finalization.
Temporarily restricts OWNERS to ensure T remains stable until
a long term static analysis solution is found.
Fixes the script for finalization to handle split files and
seed the next release's staging-public-group blocks.
Bug: 222537368
Test: manual, checked build before and after mock finalization
Change-Id: I901a80e487f5eaab9689f469196648535857e0e1
8d4fc82250