[skotty] Pre-initialize animated props

Force an initial tick on animation initialization.

This prevents inconsistent state flashing if the client starts rendering
before the first tick.

TBR=
Change-Id: Iaec3146b4085c980e6501d6a65dd8f2421a2895f
Reviewed-on: https://skia-review.googlesource.com/92740
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>

experimental/skotty/Skotty.cpp

@@ -897,6 +897,9 @@ Animation::Animation(const ResourceProvider& resources,
     AttachContext ctx = { resources, assets, fAnimators };
     fDom = AttachComposition(json, &ctx);
 
+    // In case the client calls render before the first tick.
+    this->animationTick(0);
+
     LOG("** Attached %d animators\n", fAnimators.count());
 }