Fixed minor typo in sample of BluetoothLEHelper.md

[szv]

What changes to the docs does this PR provide?

Fixes a minor typo if your choice to of your choice.

PR Checklist

Please check if your PR fulfills the following requirements:

• Correctly picked the right branch to base the change off (dev for new features, main for typos/improvements)
• For new pages, used the provided template
• For new features, added an entry in the Table of Contents
• Ran against a spell and grammar checker
• Contains NO breaking changes

[learn-build-service-prod]

Learn Build status updates of commit d63ad60:

✅ Validation status: passed

File	Status	Preview URL	Details
docs/helpers/BluetoothLEHelper.md	✅Succeeded	View

For more details, please refer to the build report.

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