[skottie] Text selector ease-high/ease-low support

Change-Id: Ia879868df677cabca6d5fcd09845efdb6147ee8e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/238177
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
3 files changed