Keep non-layout animations on the synchronous path while another view animates layout

[bartlomiejbloniarz]

Summary:

The shared animation backend decided per surface whether a frame's animated props go through a shadow tree commit or straight to the mounted views. As soon as one view animated a layout prop, every animated view on that surface went through the commit path for the whole animation, including views that only animate transform or opacity. Besides the extra commit work, on Android this moved those views from updatePropsSynchronously to regular mounts. There the synchronous mount props cache (overrideBySynchronousMountPropsAtMountingAndroid) replaced the incoming transform with its last synchronously written value, so the view froze while the other view's layout animation ran and jumped when it ended.

The decision is now made per view. SurfaceUpdates holds a surface's mutations keyed by view tag, and applySurfaceUpdates splits them into views with layout updates, which go through commitUpdates, and the rest, which are applied synchronously. AnimationMutation and AnimationMutations move to AnimationMutation.h, still included by AnimationBackend.h. AnimatedPropsRegistry::update reads the frame's batches instead of the merged per-surface map.

Changelog:

[General] [Fixed] - A view animating only non-layout props on the shared animation backend no longer freezes while another view on the surface animates a layout prop

Test Plan:

• New Fantom test "non-layout props stay on the direct path while another view animates layout": one view animates transform while a sibling animates height. The transform must reach the direct-manipulation props. It fails before this change and passes after.
• AnimatedBackend-itest.js and Animated-itest.js pass.