Fix encoding for gradlew.bat files

[yungsters]

Summary

Fixing some encoding issues with gradlew.bat files. The issues seem to have been introduced by 85249ca.

This is creating problems for the bot that syncs code between Facebook and GitHub.

Changelog

[Internal]

Test Plan

Manually shasum the files between Facebook and GitHub repositories.

[analysis-bot]

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

Base commit: 504cbf1

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	8,956,950	+0
android	hermes	armeabi-v7a	8,488,301	+0
android	hermes	x86	9,378,218	+0
android	hermes	x86_64	9,342,384	+0
android	jsc	arm64-v8a	10,638,877	+0
android	jsc	armeabi-v7a	9,557,750	+0
android	jsc	x86	10,654,421	+0
android	jsc	x86_64	11,262,275	+0

Base commit: 504cbf1