Only schedule Choreographer callbacks if there's an active animation

[itsjohnward]

Summary: Changelog: [Internal] A very similar diff was attempted with D50647971 and reverted in D51617862. The main difference here is all behavior is gated behind the feature flag. Before, we were enqueuing the extra frame callback on start_animating_node even if ondemand choreographer was disabled.

Reviewed By: sammy-SC

Differential Revision: D56085369

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	19,478,552	+21
android	hermes	armeabi-v7a	n/a	--
android	hermes	x86	n/a	--
android	hermes	x86_64	n/a	--
android	jsc	arm64-v8a	22,851,093	+56
android	jsc	armeabi-v7a	n/a	--
android	jsc	x86	n/a	--
android	jsc	x86_64	n/a	--

Base commit: d77f80696037b9c87a576d9e1150829b7c867870 Branch: main