GMs: re-sort gni, script to regenerate gni, file name convention

Change-Id: I4b61c2a66f8d6b2d8c4a5ffd8c373b643415c70c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/211598
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
7 files changed