Added lower and upper case distinction for content encoding.

[Robert-SD]

This should fix issue #895. It enables data synchronization with Kraken API again. Many thanks @CedricCabessa for outlining the reason for the issue.

[Armonistas]

Hello Robert. Since the app hasn't updated on play store from the developer, how can we build an apk with this change?

[nachofq]

I have the same question! It was an awesome app we should bring it back to life!

[STRML]

@MaciejCiemiega, I think you're likely to see more breakage over time until this fix is committed and a new version released. The main reason is HTTP/2 compatibility, even for non-HTTP/2 clients. In order to simplify internal code, many major servers and proxies now only send along case-insensitive headers. This affects Apache, Nginx, and now HAProxy as of 2.0-2.1 with its new internal HTX representation.

The HTTP spec has never specified case-sensitive headers names, and Volley fixed its erroneous handling of headers on responses in google/volley#91.

Short of pulling in a new version of Volley and using NetworkResponse.toHeaderMap(List<Header>), which is more correct but may be more work than you want to do, this patch fixes the issue, and should fix parsing errors on Binance, Kraken, BitMEX, and others.