I'm attempting to implement the Initializing Flutterfire FutureBuilder approach with Flutter 1.20 and hitting the following exception:

$ flutter --version
Flutter 1.20.3 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 216dee60c0 (7 days ago) • 2020-09-01 12:24:47 -0700
Engine • revi

Google suggests enabling gzip compression before transferring files over the network:

In order to receive a gzip-encoded response you must do two things: Set an Accept-Encoding header, and modify your user agent to contain the string gzip. Here is an example of properly formed HTTP headers for enabling gzip compression:

Acc