Fix issue with HttpCache causes HttpParseException

[sav007]

When app is freshly installed (or when there is no cached response)
When HttpLoggingInterceptor is added to OkHttp
Log level is set to BODY
The issues is that HttpLoggingInterceptor when logging response body requests whole response https://github.com/square/okhttp/blob/master/okhttp-logging-interceptor/src/main/java/okhttp3/logging/HttpLoggingInterceptor.kt#L244-L246
that causes ApolloParseInterceptor to fail as there was a bug in our http cache: we didn't properly buffer original response, so instead of giving buffered response to ApolloParseInterceptor we give it non-buffered, that obviously will fail as response already was read from the source.

Closes #1786