Honor system proxy settings when downloading crashlytics.jar, fix #6765…

… (#6817)

* Work around ruby defect #12724, where HTTP#get_response and HTTP#post_form don't use ENV proxy settings (#6765)

* fixed code style as per PR guidelines

* added link to ruby defect, changed raise to UI.error! are per reviewers request

fastlane/lib/fastlane/helper/crashlytics_helper.rb

@@ -72,8 +72,14 @@ def download_android_tools
           begin
             UI.important("Downloading Crashlytics Support Library - this might take a minute...")
 
-            result = Net::HTTP.get(URI(url))
-            File.write(zip_path, result)
+            # Work around ruby defect, where HTTP#get_response and HTTP#post_form don't use ENV proxy settings
+            # https://bugs.ruby-lang.org/issues/12724
+            uri = URI(url)
+            http_conn = Net::HTTP.new(uri.host, uri.port)
+            http_conn.use_ssl = true
+            result = http_conn.request_get(uri.path)
+            UI.error! "#{result.message} (#{result.code})" unless result.kind_of? Net::HTTPSuccess
+            File.write(zip_path, result.body)
 
             # Now unzip the file
             Action.sh "unzip '#{zip_path}' -d '#{containing}'"