[skottie] Switch animators to SkTArray

TBR=

Change-Id: I8acc02f176e7dffd344456ad4cc39936e9a9618f
Reviewed-on: https://skia-review.googlesource.com/101000
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
1 file changed