Fix issue with parsing JSON response in incorrect CP1251 encoding

[accidbright]

Issue: https://github.com/googleads/googleads-consent-sdk-ios/issues/13

[googlebot]

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[accidbright]

I signed it!

[googlebot]

CLAs look good, thanks!

[Izzyjm]

when will this be merged ? @googlebot why are there alot of issues you guys reviewed but have not merged ?