fix ReadableArray annotations

[dulmandakh]

Summary

Fix ReadableArray annotations, because these methods throw ArrayIndexOutOfBoundsException instead of null if index is not found.

Changelog

[Android] [Changed] - fix ReadableArray null annotations. Possibly breaking change for Kotlin apps.

Test Plan

RNTester app builds and runs as expected, and show correct type in when used with Kotlin code.

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
ios	-	universal	n/a	--

Base commit: 4d4992c

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	7,385,801	0
android	hermes	armeabi-v7a	7,013,117	0
android	hermes	x86	7,828,013	0
android	hermes	x86_64	7,717,499	0
android	jsc	arm64-v8a	9,532,102	0
android	jsc	armeabi-v7a	9,147,130	0
android	jsc	x86	9,396,778	0
android	jsc	x86_64	9,978,488	0

Base commit: 4d4992c

[facebook-github-bot]

@fkgozali has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[react-native-bot]

This pull request was successfully merged by @dulmandakh in d765565.

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