fix(data_connect)!: Correct UTF-8 decoding for international characters

[ska2519]

Description

Previously, text containing characters from languages such as Korean, which are encoded in UTF-8, was not being decoded correctly. This resulted in characters appearing garbled or "broken".

This commit updates the decoding logic to properly handle UTF-8 encoding, ensuring correct display and processing of international text.

Related Issues

[firebase_data_connect] Response data Correct UTF-8 decoding for international characters Fixes #17290

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