perf: Drive Android CSS platform transitions from a single frame pump

[MatiPl01]

Replaces the per-view ObjectAnimator engine behind Android platform CSS transitions with a single Choreographer frame callback that drives all running transitions, and batches the JS-to-UI command stream into one main-looper message per burst instead of one per transition.

ObjectAnimator fought CSS semantics in six places (delay, pre-start value writes, seek-before-start, isRunning quirks, duration scale, end-listener identity). Computing each frame from an absolute start timestamp handles delay, late starts and interruption resume directly, so all of those workarounds go away. This also stops ObjectAnimator from strongly holding views (API 35+) and removes per-frame allocations in the commit-repair pass.

Measured on an API 36 emulator (hardware GL, debug build, dev JS): 504 views with opacity transitions, 4 scenarios, median frame time in ms and frames drawn per 30s, mean of 3 runs. Each run used a freshly booted emulator with a checksum-verified install, and every measurement window was bracketed by health probes to reject degraded runs.

scenario	plain loop	sync UI props	ObjectAnimator engine	frame pump
churn, 20 re-renders/sec	81.0 / 651	30.3 / 1724	24.3 / 1788	23.3 / 1799
churn, 5 re-renders/sec	81.0 / 655	30.7 / 1715	24.7 / 1789	22.0 / 1793
pulse, all views every 2s	27.7 / 728	22.7 / 762	17.0 / 611	17.0 / 656
stagger, 0-500ms delays	33.3 / 995	24.3 / 1032	20.7 / 994	18.3 / 1011

Jank under churn: 0.1-0.8% (pump) vs 4.4-4.6% (sync UI props). Pulse and stagger show similar frame counts for all engines because few views animate at any moment, so nothing is pressured into dropping frames; the differences there are in frame time.

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[MatiPl01]

Superseded by #10170, which rebuilds the frame pump on top of the mount-gated repair (#10168) and the interned JNI ids (#10169). Device measurements for the final stack are in the benchmark report.