Fix HeadlessJsTaskContext creating Handler on background thread

[javache]

Summary: D54496604 fixed lifecycle methods for JavaTimerManager, which now reveals another bug. Because this codepath ends up creating a HeadlessJsTaskContext which in turn creates a Handler, ReactInstance destruction doesn't complete cleanly.

2024-05-15 17:42:52.935 12681 27113 W fb4a.BridgelessReact: ReactHost{1}.getOrCreateDestroyTask(): React destruction failed. ReactInstance task faulted. Fault reason: Can't create handler inside thread Thread[pool-51-thread-1,5,main] that has not called Looper.prepare(). Destroy reason: FbReactInstanceHolder.destroyReactManager(): FbReactInstanceLogoutCleaner.clearReactInstanceData()

The fix is to not create our own Handler, but instead use the shared methods in UiThreadUtil.

Differential Revision: D57378247

[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D57378247

[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D57378247

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	19,526,129	-17
android	hermes	armeabi-v7a	n/a	--
android	hermes	x86	n/a	--
android	hermes	x86_64	n/a	--
android	jsc	arm64-v8a	22,896,050	+2
android	jsc	armeabi-v7a	n/a	--
android	jsc	x86	n/a	--
android	jsc	x86_64	n/a	--

Base commit: 524e3eec3e73f56746ace8bef569f36802a7a62e Branch: main

[facebook-github-bot]

This pull request has been merged in facebook/react-native@e67d5560cfd35f07ce74cfcc12555346a6f0e865.

[github-actions[bot]]

This pull request was successfully merged by @javache in e67d5560cfd35f07ce74cfcc12555346a6f0e865.

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