[skottie] Guard against missing solid layer color property

Bug: skia:8281
Change-Id: I4a5d5e37d3b1bb0995c20ad138e8e234869ed760
Reviewed-on: https://skia-review.googlesource.com/148999
Commit-Queue: Florin Malita <fmalita@chromium.org>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Auto-Submit: Florin Malita <fmalita@chromium.org>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
1 file changed