Drop patches which were removed from cromite

- AImageReader CFI crash mitigations
Dropped as chromium no longer supports Android 9
https://github.com/uazo/cromite/commit/1a0a344a83202b66f2b4e7a2ebca21135da166d9

- Enable prefetch privacy changes by default
Dropped as it was merged with Add custom tabs intent privacy option
patch
https://github.com/uazo/cromite/commit/454dfbf1925437f36fdd0c44da846d334f487846