getHeaderFields

HTTP headerFields using user agent keys defined in https://wicg.github.io/ua-client-hints/

Sec-CH-UA: "SnabbleSdkSample";v="1" Sec-CH-UA-Full-Version-List: "SnabbleSdkSample";v="1.0-1","SDK";v="dev" Sec-CH-UA-Platform: Android Sec-CH-UA-Platform-Version: 34 Sec-CH-UA-Arch: Google;sdk_gphone64_arm64