This is a reland of commit 6f0d2bf494
Includes a fix for iOS codesigning script to be python3 compatible.
Original change's description:
> Set GN's script_executable to "python3"
>
> In some environments, GN would end up running scripts with python2.
> This change requires that python3 be in the path, but is the safest
> way to guarantee that all scripts are run correctly.
>
> Change-Id: Ifc2601ff9c9f3705ac7f1057a26a87a61211ff67
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/528337
> Reviewed-by: Kevin Lubick <kjlubick@google.com>
> Commit-Queue: Brian Osman <brianosman@google.com>
Change-Id: I785909f3c7d51d6fd1c90114d01f114be76981f2
Cq-Include-Trybots: luci.skia.skia.primary:Build-Mac-Clang-arm64-Debug-iOS
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/528441
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1843bee81d