Automatically set -Oz when skia_enable_optimize_size is true

Bug: skia:13657
Change-Id: Idf2efc33e380a375d213bb56783c682d0a525abc
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/583238
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
3 files changed